Mohammad Aslam Khan Khalil

Mohammad Aslam Khan Khalil
Mohammad Aslam Khan Khalil
Born	January 7, 1950 (age 73); Jhansi, U.P., India

Last updated December 24, 2023

Mohammad Aslam Khan Khalil, M.A.K. Khalil or Aslam Khalil (born January 7, 1950) is a theoretical physicist known for his leading research in atmospheric physics. Early in his career, he worked on quantum field theory of elementary particles. During the last three decades, he has worked on Global Change Science, including the physics, chemistry and biology of greenhouse gases and ozone depleting compounds. He is a professor of physics at Portland State University.^[1]

Selected publications

Scientific papers, books and articles

M.A.K.Khalil. Global Climate Change and Human Life, J. Wiley & Sons, UK., 2022. ISBN 9780470665787

M.A.K. Khalil. Non-CO₂ greenhouse gases in the atmosphere. Annual Review of Energy/Environment, Annual Reviews, 1999, Vol. 24: 245–261, 1999.

M.A.K.Khalil. Earth’s atmosphere. Encyclopedia of Geochemistry, Encyclopedia of Earth Sciences Series, C.P. Marshall and R.W. Fairbridge, Editors, Kluwer Academic Publishers, p. 143–145, 1999.

M.A.K. Khalil, R.A. Rasmussen, M.J. Shearer, R.W. Dalluge, L.X. Ren, and C.-L. Duan; Measurements of methane emissions from rice fields in China. J. Geophys. Res., 103(D19): 25,181–25,210, 1998.

M.A.K. Khalil, R.A. Rasmussen, M.J. Shearer, Z.-L. Chen, H. Yao, and Y. Jun; Emissions of methane, nitrous oxide, and other trace gases from rice fields in China. J. Geophys. Res., 103(D19): 25,241–25,250, 1998.

M.A.K. Khalil, M.J. Shearer, and R.A.Rasmussen, Atmospheric methane over the last century.World Resource Review, 8(4): 481–492, 1996.

Y. Lu and M.A.K. Khalil. The distribution of solar radiation in the Earth’s atmosphere: The effects of ozone, aerosols, and clouds. Chemosphere, 32(4): 739–758, 1996.

M.A.K. Khalil. Greenhouse gases in the earth’s atmosphere. Encyclopedia of Environmental Biology, Volume 2, W.A. Nirenberg, Editor, Academic Press, Florida, p. 251–265, 1995.

M.A.K. Khalil and R.A. Rasmussen. The global sources of nitrous oxide. J. Geophys. Res., 97(D13):14651-14660, 1992.

R.M. MacKay and M.A.K. Khalil; Theory and development of a one-dimensional time-dependent radiative convective climate model. Chemosphere, 22(3–4):383–417, 1991.

M. A. K. Khalil and F. P. Moraes. Linear least squares method for time series analysis with an application to a methane time series. Journal of the Air and Waste Management Association, 45, Jan 1995.

Bibliography

Atmospheric Methane by Mohammad Aslam Khan Khalil (1993, 2000)

Related Research Articles

<span class="mw-page-title-main">Global warming potential</span> Potential heat absorbed by a greenhouse gas

Global warming potential (GWP) is an index to measure of how much infrared thermal radiation a greenhouse gas would absorb over a given time frame after it has been added to the atmosphere. The GWP makes different greenhouse gases comparable with regards to their "effectiveness in causing radiative forcing". It is expressed as a multiple of the radiation that would be absorbed by the same mass of added carbon dioxide, which is taken as a reference gas. Therefore, the GWP is one for CO₂. For other gases it depends on how strongly the gas absorbs infrared thermal radiation, how quickly the gas leaves the atmosphere, and the time frame being considered.

<span class="mw-page-title-main">Nitrous oxide</span> Colourless non-flammable gas

Nitrous oxide, commonly known as laughing gas, nitrous, nitro, or nos, is a chemical compound, an oxide of nitrogen with the formula N^₂O. At room temperature, it is a colourless non-flammable gas, and has a slightly sweet scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidiser similar to molecular oxygen.

The mesopause is the point of minimum temperature at the boundary between the mesosphere and the thermosphere atmospheric regions. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, the mesosphere is the coldest region on Earth with temperatures as low as -100 °C. The altitude of the mesopause for many years was assumed to be at around 85 km (53 mi), but observations to higher altitudes and modeling studies in the last 10 years have shown that in fact there are two mesopauses - one at about 85 km and a stronger one at about 100 km (62 mi), with a layer of slightly warmer air between them.

The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth creates pressure, absorbs most meteoroids and ultraviolet solar radiation, warms the surface through heat retention, allowing life and liquid water to exist on the Earth's surface, and reduces temperature extremes between day and night.

<span class="mw-page-title-main">Ground-level ozone</span> Constituent gas of the troposphere

Ground-level ozone (O₃), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface. The troposphere extends from the ground up to a variable height of approximately 14 kilometers above sea level. Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. Ground-level or tropospheric ozone is created by chemical reactions between NOx gases (oxides of nitrogen produced by combustion) and volatile organic compounds (VOCs). The combination of these chemicals in the presence of sunlight form ozone. Its concentration increases as height above sea level increases, with a maximum concentration at the tropopause. About 90% of total ozone in the atmosphere is in the stratosphere, and 10% is in the troposphere. Although tropospheric ozone is less concentrated than stratospheric ozone, it is of concern because of its health effects. Ozone in the troposphere is considered a greenhouse gas, and may contribute to global warming.

Radiative forcing is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured in watts per meter squared. It is a scientific concept used to quantify and compare the external drivers of change to Earth's energy balance. These external drivers are distinguished from climate feedbacks and internal variability, which also influence the direction and magnitude of imbalance.

Paul Jozef Crutzen was a Dutch meteorologist and atmospheric chemist. He and Mario Molina and Frank Sherwood Rowland were awarded the Nobel Prize in Chemistry in 1995 for their work on atmospheric chemistry and specifically for his efforts in studying the formation and decomposition of atmospheric ozone. In addition to studying the ozone layer and climate change, he popularized the term Anthropocene to describe a proposed new epoch in the Quaternary period when human actions have a drastic effect on the Earth. He was also amongst the first few scientists to introduce the idea of a nuclear winter to describe the potential climatic effects stemming from large-scale atmospheric pollution including smoke from forest fires, industrial exhausts, and other sources like oil fires.

Trace gases are gases that are present in small amounts within an environment such as a planet's atmosphere. Trace gases in Earth's atmosphere are gases other than nitrogen (78.1%), oxygen (20.9%), and argon (0.934%) which, in combination, make up 99.934% of its atmosphere.

<span class="mw-page-title-main">Non-methane volatile organic compound</span>

Non-methane volatile organic compounds (NMVOCs) are a set of organic compounds that are typically photochemically reactive in the atmosphere—marked by the exclusion of methane. NMVOCs include a large variety of chemically different compounds, such as benzene, ethanol, formaldehyde, cyclohexane, 1,1,1-trichloroethane and acetone. Essentially, NMVOCs are identical to volatile organic compounds (VOCs), but with methane excluded. Methane is excluded in air-pollution contexts because it is not toxic. It is however a very potent greenhouse gas, with low reactivity and thus a long lifetime in the atmosphere. An important subset of NMVOCs are the non-methane hydrocarbons (NMHCs).

The infrared atmospheric window refers to a region of the infrared spectrum where there is relatively little absorption of terrestrial thermal radiation by atmospheric gases. The window plays an important role in the atmospheric greenhouse effect by maintaining the balance between incoming solar radiation and outgoing IR to space. In the Earth's atmosphere this window is roughly the region between 8 and 14 μm although it can be narrowed or closed at times and places of high humidity because of the strong absorption in the water vapor continuum or because of blocking by clouds. It covers a substantial part of the spectrum from surface thermal emission which starts at roughly 5 μm. Principally it is a large gap in the absorption spectrum of water vapor. Carbon dioxide plays an important role in setting the boundary at the long wavelength end. Ozone partly blocks transmission in the middle of the window.

In atmospheric chemistry, NO_x is shorthand for nitric oxide and nitrogen dioxide, the nitrogen oxides that are most relevant for air pollution. These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone.

Jerry Mahlman was an American meteorologist and climatologist.

This is a list of climate change topics.

<span class="mw-page-title-main">LBLRTM</span> Radiation transfer model

Within atmospheric science, LBLRTM - The Line-By-Line Radiative Transfer Model is an accurate, efficient and highly flexible model for calculating spectral transmittance and radiance.

<span class="mw-page-title-main">Greenhouse gas</span> Gas in an atmosphere that absorbs and emits radiation at thermal infrared wavelengths

Greenhouse gases are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect. The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by water vapor (H₂O), carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and ozone (O₃). Without greenhouse gases, the average temperature of Earth's surface would be about −18 °C (0 °F), rather than the present average of 15 °C (59 °F).

Atmospheric methane is the methane present in Earth's atmosphere. The concentration of atmospheric methane is increasing due to methane emissions, and is causing climate change. Methane is one of the most potent greenhouse gases. Methane's radiative forcing (RF) of climate is direct, and it is the second largest contributor to human-caused climate forcing in the historical period. Methane is a major source of water vapour in the stratosphere through oxidation; and water vapour adds about 15% to methane's radiative forcing effect. The global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe. That means it traps 84 times more heat per mass unit than carbon dioxide (CO₂) and 105 times the effect when accounting for aerosol interactions.

<span class="mw-page-title-main">Greenhouse gas monitoring</span> Measurement of greenhouse gas emissions and levels

Greenhouse gas monitoring is the direct measurement of greenhouse gas emissions and levels. There are several different methods of measuring carbon dioxide concentrations in the atmosphere, including infrared analyzing and manometry. Methane and nitrous oxide are measured by other instruments. Greenhouse gases are measured from space such as by the Orbiting Carbon Observatory and networks of ground stations such as the Integrated Carbon Observation System.

Greenhouse gas emissions from wetlands of concern consist primarily of methane and nitrous oxide emissions. Wetlands are the largest natural source of atmospheric methane in the world, and are therefore a major area of concern with respect to climate change. Wetlands account for approximately 20 - 30% of atmospheric methane through emissions from soils and plants, and contribute an approximate average of 161 Tg of methane to the atmosphere per year.

Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.

Akkihebbal Ramaiah (Ravi) Ravishankara ForMemRS FAAAS FRSC is a scientist specializing in Chemistry and Atmospheric Sciences, and University Distinguished Professor in the Departments of Chemistry and Atmospheric Sciences at Colorado State University, Fort Collins.

References

↑ "Bio, Mohammad Aslam Khan Khalil". Archived from the original on 2009-01-30. Retrieved 2008-03-07.

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[1] "Bio, Mohammad Aslam Khan Khalil". Archived from the original on 2009-01-30. Retrieved 2008-03-07.

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