Application of the Superslow Relaxation Model in the Description of Time Series of the Vertical Electric Field Component in the Earth’s Atmospheric Boundary Layer in the Infra-Low Frequency Range

The field in the entrance pupil of a high NA lens can be optimized such that, for given incident power, the electric field component in a given direction in the focal point is maximum. If the field component is chosen parallel to the optical axis, the longitudinal component is maximized and it is found that the optimum longitudinal component is narrower than the Airy spot. We discuss how this can be used to obtain higher resolution in photolithography when a resist is used that is sensitive to only the longitudinal component. We describe a proposition for realizing such resist.

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Study of Thermal Activity in The Mixing Layer During First Generated Single Cloud by Using Combined Observation From Boundary Layer Radar, Doppler Lidar and Time Lapse Camera

10.5194/egusphere-egu21-14016 ◽

2021 ◽

Author(s):

Ginaldi Ari Nugroho ◽

Kosei Yamaguchi ◽

Eiichi Nakakita ◽

Masayuki K. Yamamoto ◽

Seiji Kawamura ◽

...

Keyword(s):

Boundary Layer ◽

Time Series ◽

Atmospheric Boundary Layer ◽

Vertical Velocity ◽

Time Lapse ◽

Small Scale ◽

Thermal Activity ◽

Doppler Lidar ◽

Cumulus Cloud ◽

Scale Perturbation

<p>Detailed observation of small scale perturbation in the atmospheric boundary layer during the first generated cumulus cloud are conducted. Our target is to study this small scale perturbation, especially related to the thermal activity at the first generated cumulus cloud. The observation is performed during the daytime on August 17, 2018, and September 03, 2018. Location is focused in the urban area of Kobe, Japan. High-resolution instruments such as Boundary Layer Radar, Doppler Lidar, and Time Lapse camera are used in this observation. Boundary Layer Radar, and Doppler Lidar are used for clear air observation. Meanwhile Time Lapse Camera are used for cloud existence observation. The atmospheric boundary layer structure is analyzed based on vertical velocity profile, variance, skewness, and estimated atmospheric boundary layer height. Wavelet are used to observe more of the period of the thermal activity. Furthermore, time correlation between vertical velocity time series from height 0.3 to 2 km and image pixel of generated cloud time series are also discussed in this study.</p>

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Fluctuating boundary layer on a magnetized plate

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100041463 ◽

1967 ◽

Vol 63 (2) ◽

pp. 513-525 ◽

Cited By ~ 11

Author(s):

Sahib Singh Chawla

Keyword(s):

Boundary Layer ◽

Low Frequency ◽

Surface Current ◽

Frequency Range ◽

Mean Flow ◽

Wave Type ◽

High Frequencies ◽

Phase Lead ◽

The Mean ◽

The Magnetic Field

The laminar boundary layer on a magnetized plate, when the magnetic field oscillates in magnitude about a constant non-zero mean, is analysed. For low-frequency fluctuations the solution is obtained by a series expansion in terms of a frequency parameter, while for high frequencies the flow pattern is of the ‘skin-wave’ type unaffected by the mean flow. In the low-frequency range, the phase lead and the amplitude of the skin-friction oscillations increase at first and then decrease to their respective ‘skin-wave’ values. On the other hand the phase angle of the surface current decreases from 90° to 45° and its amplitude increases with frequency.

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On modeling airborne very low‐frequency measurements

Geophysics ◽

10.1190/1.1442627 ◽

1989 ◽

Vol 54 (12) ◽

pp. 1596-1606 ◽

Cited By ~ 6

Author(s):

Ari Poikonen ◽

Ilkka Suppala

Keyword(s):

Plane Wave ◽

Electric Field ◽

Numerical Models ◽

Vertical Component ◽

Low Frequency ◽

Primary Field ◽

Vertical Electric Field ◽

Inhomogeneous Plane ◽

Inhomogeneous Plane Wave ◽

Attenuation Characteristics

Numerical models employed in ground VLF modeling use a normally incident (homogeneous) plane wave as a primary field. We show that these models are not directly applicable to modeling the impedance and wavetilt in the air, quantities needed in the interpretation of airborne VLF resistivity measurements. Instead, the primary field must be replaced by an inhomogeneous plane wave incident on the ground at an angle close to 90 degrees in order to provide the correct behavior of the apparent resistivities in the air. VLF magnetic polarization parameters, however, can be modeled in the air using the normally incident plane wave as a primary field. We also show that the plane‐wave analysis provides the same attenuation characteristics for the wavetilt in the air that is predicted by the Norton’s surface wave obtained by using the vertical electric dipole as a source. Use of the inhomogeneous plane wave introduces the vertical component of the electric field in the model. A 2‐D modeling technique based on the network solution is used to demonstrate the effects of the vertical electric field in the H‐polarization case. The vertical electric field generates charge distributions on the horizontal boundaries of conductors. In the case of a vertical sheet‐like conductor, these charges cause a slight asymmetry in apparent‐resistivity anomalies. Attenuation characteristics of various VLF anomalies with altitude are also presented. The H‐polarization anomalies attenuate much more rapidly in the air than those for E‐polarization due to the difference in the dominating source of EM fields in each polarization.

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Direct observation of a tangential electric field component at the magnetopause

Geophysical Research Letters ◽

10.1029/gl006i004p00305 ◽

1979 ◽

Vol 6 (4) ◽

pp. 305-308 ◽

Cited By ~ 40

Author(s):

F. S. Mozer ◽

R. B. Torbert ◽

U. V. Fahleson ◽

C.-G. Fälthammar ◽

A. Gonfalone ◽

...

Keyword(s):

Electric Field ◽

Direct Observation ◽

Field Component ◽

Electric Field Component ◽

Tangential Electric Field

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Multiple technical observations of the atmospheric boundary layer structure of a red warning haze episode in Beijing

10.5194/amt-2018-391 ◽

2019 ◽

Author(s):

Yu Shi ◽

Fei Hu ◽

Guangqiang Fan ◽

Zhe Zhang

Keyword(s):

Boundary Layer ◽

Air Pollution ◽

Atmospheric Boundary Layer ◽

Extinction Coefficient ◽

Layer Structure ◽

Low Frequency ◽

Inverse Correlation ◽

Hygroscopic Growth ◽

Boundary Layer Structure ◽

Haze Pollution

Abstract. The study and control of air pollution need to detect the structure of atmospheric boundary layer (ABL) in order to understand the mechanism of interaction between atmospheric boundary layer and air pollution. However, when extreme pollution occurs, the detection of atmospheric boundary layer structure is very scarce. Beijing, the capital of China, has experienced a severe haze pollution in December 2016. The city issued its first red air pollution warning of this year (the highest PM2.5 concentration was later monitored to exceed 450 μg m−3). In this paper, the vertical profiles of wind, temperature, humidity and extinction coefficient (reflecting aerosol concentration), as well as ABL heights and turbulence quantities under heavy haze pollution are analyzed, with collected data from Lidar, wind profile radar (WPR), radiosonde, 325-meter meteorological tower (equipped with 7-layer supersonic anemometer and 15-layer low frequency wind, temperature and humidity sensors) and some other ground observations. ABL heights obtained by three different methods based on Lidar extinction coefficient data (Hc) are compared with the heights calculated from radiosonde temperature data (Hθ) and from WPR wind speed data (Hu). The results show that increase of water vapor has greatly promoted the hygroscopic growth of aerosols, the corresponding extinction coefficients also increased significantly. The PBL heights Hθ and Hu of heavy haze pollution day were generally lower than those of clean day, but Hc increased. Turbulent activities were great inhibited during haze pollution, time changes of both friction velocity (u*) and turbulent kinetic energy (TKE) have obvious inverse correlation with that of PM2.5. The results of this paper could provide some reference for the parameterization of the boundary layer height and turbulent diffusion process in the numerical model of severe air pollution.

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