Non-local thermodynamic kinetic temperature retrieval from measurements of CO_2 15 µm earth limb emission

2001 ◽  
Author(s):  
Christopher Mertens
Keyword(s):  
Kinetic Temperature ◽  
Non Local ◽  
Temperature Retrieval

scholarly journals On the quality of MIPAS kinetic temperature in the middle atmosphere

2012 ◽  
Vol 12 (13) ◽  
pp. 6009-6039 ◽  
Author(s):  
M. García-Comas ◽  
B. Funke ◽  
M. López-Puertas ◽  
D. Bermejo-Pantaleón ◽  
N. Glatthor ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
High Spectral Resolution ◽  
Retrieval Algorithm ◽  
Kinetic Temperature ◽  
Random Errors ◽  
Noctilucent Cloud ◽  
Mauna Loa ◽  
Falling Sphere ◽  
Non Local

Abstract. The kinetic temperature and line of sight elevation information are retrieved from the MIPAS Middle Atmosphere (MA), Upper Atmosphere (UA) and NoctiLucent-Cloud (NLC) modes of high spectral resolution limb observations of the CO2 15 μm emission using the dedicated IMK/IAA retrieval algorithm, which considers non-local thermodynamic equilibrium conditions. These variables are accurately derived from about 20 km (MA) and 40 km (UA and NLC) to 105 km globally and both at daytime and nighttime. Typical temperature random errors are smaller than 0.5 K below 50 km, 0.5–2 K at 50–70 km, and 2–7 K above. The systematic error is typically 1 K below 70 km, 1–3 K from 70 to 85 km and 3–11 K from 85 to 100 km. The average vertical resolution is typically 4 km below 35 km, 3 km at 35–50 km, 4–6 km at 50–90 km, and 6–10 km above. We compared our MIPAS temperature retrievals from 2005 to 2009 with co-located ground-based measurements from the lidars located at the Table Mountain Facility and Mauna Loa Observatory, the SATI spectrograph in Granada (Spain) and the Davis station spectrometer, and satellite observations from ACE-FTS, Aura-MLS and TIMED-SABER from 20 km to 100 km. We also compared MIPAS temperatures with the high latitudes climatology from falling sphere measurements. The comparisons show very good agreement, with differences smaller than 3 K below 85–90 km in mid-latitudes. Differences over the poles in this altitude range are larger but can be generally explained in terms of known biases of the other instruments. The comparisons above 90 km worsen and MIPAS retrieved temperatures are always larger than other instrument measurements.

scholarly journals Retrieval of Kinetic Temperature and Carbon Dioxide Abundance From Non-Local Thermodynamic Equilibrium Limb Emission Measurements Made by the SABER Experiment on the TIMED Satellite

2003 ◽  
Author(s):  
Christopher J. Mertens ◽  
Martin G. Mlynczak ◽  
Manuel Lopez-Puertas ◽  
Peter P. Wintersteiner ◽  
Richard H. Picard ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Thermodynamic Equilibrium ◽  
Local Thermodynamic Equilibrium ◽  
Kinetic Temperature ◽  
Non Local

scholarly journals New insights for mesospheric OH: multi-quantum vibrational relaxation as a driver for non-local thermodynamic equilibrium

2018 ◽  
Vol 36 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Konstantinos S. Kalogerakis ◽  
Daniel Matsiev ◽  
Philip C. Cosby ◽  
James A. Dodd ◽  
Stefano Falcinelli ◽  
...  
Keyword(s):  
Thermodynamic Equilibrium ◽  
Vibrational Relaxation ◽  
Local Thermodynamic Equilibrium ◽  
Vibrational Excitation ◽  
Kinetic Temperature ◽  
Population Distributions ◽  
Vibrational Levels ◽  
Non Local ◽  
Relationship Of ◽  
The Relationship

Abstract. The question of whether mesospheric OH(v) rotational population distributions are in equilibrium with the local kinetic temperature has been debated over several decades. Despite several indications for the existence of non-equilibrium effects, the general consensus has been that emissions originating from low rotational levels are thermalized. Sky spectra simultaneously observing several vibrational levels demonstrated reproducible trends in the extracted OH(v) rotational temperatures as a function of vibrational excitation. Laboratory experiments provided information on rotational energy transfer and direct evidence for fast multi-quantum OH(high-v) vibrational relaxation by O atoms. We examine the relationship of the new relaxation pathways with the behavior exhibited by OH(v) rotational population distributions. Rapid OH(high-v) + O multi-quantum vibrational relaxation connects high and low vibrational levels and enhances the hot tail of the OH(low-v) rotational distributions. The effective rotational temperatures of mesospheric OH(v) are found to deviate from local thermodynamic equilibrium for all observed vibrational levels. Dedicated to Tom G. Slanger in celebration of his 5 decades of research in aeronomy.

scholarly journals Effects of Non-Local Thermodynamic Equilibrium (NLTE) on Molecular Opacities

1994 ◽  
Vol 146 ◽  
pp. 234-249
Author(s):  
Hollis R. Johnson
Keyword(s):  
Chemical Composition ◽  
Energy Budget ◽  
Local Thermodynamic Equilibrium ◽  
Stellar Atmospheres ◽  
Kinetic Temperature ◽  
Circumstellar Envelope ◽  
Spectral Classification ◽  
Physical Conditions ◽  
Molecular Features ◽  
Non Local

Molecules increase in importance in stellar atmospheres as the temperature falls along the spectral sequence for all luminosity classes. Among their many roles molecular features provide the basis for spectral classification (temperature and chemical composition) in M, S, and C stars; they constitute important opacity sources across the spectrum from the ultraviolet to the infrared; they influence the energy budget and hence the kinetic temperature in the outer photospheric layers; they may contribute significantly to the radiative levitation of the atmosphere; they form masers; they may cause or facilitate mass loss; and they are indicative of physical conditions and processes from the photosphere to the outer circumstellar envelope.

scholarly journals On the quality of MIPAS kinetic temperature in the middle atmosphere

2011 ◽  
Vol 11 (8) ◽  
pp. 24233-24312 ◽  
Author(s):  
M. García-Comas ◽  
B. Funke ◽  
M. López-Puertas ◽  
D. Bermejo-Pantaleón ◽  
N. Glatthor ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
High Spectral Resolution ◽  
Retrieval Algorithm ◽  
Kinetic Temperature ◽  
Random Errors ◽  
Noctilucent Cloud ◽  
Mauna Loa ◽  
Falling Sphere ◽  
Non Local

Abstract. The kinetic temperature and line of sight elevation information are retrieved from the MIPAS Middle Atmosphere (MA), Upper Atmosphere (UA) and NoctiLucent-Cloud (NLC) modes of high spectral resolution limb observations of the CO2 15 μm emission using the dedicated IMK/IAA retrieval algorithm, which considers non-local thermodynamic equilibrium conditions. These variables are accurately derived from about 20 km (MA) and 40 km (UA and NLC) to 105 km globally and both at daytime and nighttime. Typical temperature random errors are smaller than 0.5 K below 50 km, 0.5–2 K at 50–70 km, and 2–8 K above. The systematic error is typically 1 K below 70 km, 1–3 K from 70 to 85 km and 3–11 K from 85 to 100 km. The average vertical resolution is typically 4 km below 35 km, 3 km at 35–50 km, 4–6 km at 50–90 km, and 6–10 km above. We compared our MIPAS temperature retrievals from 2005 to 2009 with co-located ground-based measurements from the lidars located at the Table Mountain Facility and Mauna Loa Observatory, the SATI spectrograph in Granada (Spain) and the Davis station spectrometer, and satellite observations from ACE-FTS, Aura-MLS and TIMED-SABER from 20 km to 100 km. We also compared MIPAS temperatures with the high latitudes climatology from falling sphere measurements. The comparisons show very good agreement, with differences smaller than 3 K below 85–90 km in mid-latitudes. Differences over the poles in this altitude range are larger but can be generally explained in terms of known biases of the other instruments. The comparisons above 90 km worsen and MIPAS retrieved temperatures are always larger than other instrument measurements.

Toward High-Resolution Low-Voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 218-219
Author(s):  
Zhifeng Shao
Keyword(s):  
Low Voltage ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Limiting Factor ◽  
Operating Voltage ◽  
Probe Radius ◽  
Non Local ◽  
Electron Microscopes ◽  
Image Position ◽  
Scanning Electron Microscopes

Recently, low voltage (≤5kV) scanning electron microscopes have become popular because of their unprecedented advantages, such as minimized charging effects and smaller specimen damage, etc. Perhaps the most important advantage of LVSEM is that they may be able to provide ultrahigh resolution since the interaction volume decreases when electron energy is reduced. It is obvious that no matter how low the operating voltage is, the resolution is always poorer than the probe radius. To achieve 10Å resolution at 5kV (including non-local effects), we would require a probe radius of 5∽6 Å. At low voltages, we can no longer ignore the effects of chromatic aberration because of the increased ratio δV/V. The 3rd order spherical aberration is another major limiting factor. The optimized aperture should be calculated as

Chromatic aberration and low-voltage SEM

1987 ◽  
Vol 45 ◽  
pp. 546-547
Author(s):  
Zhifeng Shao ◽  
A.V. Crewe
Keyword(s):  
Electron Energy ◽  
Low Voltage ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Primary Electron ◽  
Probe Size ◽  
Non Local ◽  
Optical Treatment ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

For scanning electron microscopes, it is plausible that by lowering the primary electron energy, one can decrease the volume of interaction and improve resolution. As shown by Crewe /1/, at V0 =5kV a 10Å resolution (including non-local effects) is possible. To achieve this, we would need a probe size about 5Å. However, at low voltages, the chromatic aberration becomes the major concern even for field emission sources. In this case, δV/V = 0.1 V/5kV = 2x10-5. As a rough estimate, it has been shown that /2/ the chromatic aberration δC should be less than ⅓ of δ0 the probe size determined by diffraction and spherical aberration in order to neglect its effect. But this did not take into account the distribution of electron energy. We will show that by using a wave optical treatment, the tolerance on the chromatic aberration is much larger than we expected.

Magic of signs: a non-local interpretation of homeopathy

2000 ◽  
Vol 89 (3) ◽  
pp. 127-140 ◽  
Author(s):  
H Walach
Keyword(s):  
Non Local
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