VLF remote sensing of high-energy auroral particle precipitation

Abstract. The impact of NOx and HOx production by three types of energetic particle precipitation (EPP), auroral zone medium and high energy electrons, solar proton events and galactic cosmic rays on the middle atmosphere is examined using a chemistry climate model. This process study uses ensemble simulations forced by transient EPP derived from observations with one-year repeating sea surface temperatures and fixed chemical boundary conditions for cases with and without solar cycle in irradiance. Our model results show a wintertime polar stratosphere ozone reduction of between 3 and 10 % in agreement with previous studies. EPP is found to modulate the radiative solar cycle effect in the middle atmosphere in a significant way, bringing temperature and ozone variations closer to observed patterns. The Southern Hemisphere polar vortex undergoes an intensification from solar minimum to solar maximum instead of a weakening. This changes the solar cycle variation of the Brewer-Dobson circulation, with a weakening during solar maxima compared to solar minima. In response, the tropical tropopause temperature manifests a statistically significant solar cycle variation resulting in about 4 % more water vapour transported into the lower tropical stratosphere during solar maxima compared to solar minima. This has implications for surface temperature variation due to the associated change in radiative forcing.

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Physical basis for signal separation for remote sensing of multiple high energy radiation sources

10.1117/12.2191526 ◽

2015 ◽

Author(s):

J. Richards ◽

V. K. Jain

Keyword(s):

Remote Sensing ◽

High Energy ◽

Physical Basis ◽

Signal Separation ◽

High Energy Radiation ◽

Energy Radiation ◽

Radiation Sources

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Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations

Annales Geophysicae ◽

10.5194/angeo-20-771-2002 ◽

2002 ◽

Vol 20 (6) ◽

pp. 771-779 ◽

Cited By ~ 20

Author(s):

C. Senior ◽

J.-C. Cerisier ◽

F. Rich ◽

M. Lester ◽

G. K. Parks

Keyword(s):

Convective Transport ◽

High Time Resolution ◽

Polar Cap ◽

Particle Precipitation ◽

Phase Velocities ◽

Plasma Injection ◽

Night Side ◽

Magnetospheric Boundaries ◽

Auroral Particle Precipitation ◽

Imf Clock Angle

Abstract. High-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s are observed to propagate in the sunward direction with phase velocities up to 1.5 km/s. These bursts occur over several hours of MLT in the 20:00–01:00 MLT sector, in the evening-side sunward convection. Data from a simultaneous DMSP pass and POLAR UVI images show a very contracted polar cap and extended regions of auroral particle precipitation from the magnetospheric boundaries. A DMSP pass over the Iceland-West field-of-view while one of these sporadic bursts of enhanced flow is observed, indicates that the flow bursts appear within the plasma sheet and at its outward edge, which excludes Kelvin-Helmholtz instabilities at the magnetopause boundary as the generation mechanism. In the nightside region, the precipitation is more spot-like and the convection organizes itself as clockwise U-shaped structures. We interpret these flow bursts as the convective transport following plasma injection events from the tail into the night-side ionosphere. We show that during this period, where the IMF clock angle is around 70°, the dayside magnetosphere is not completely closed.Key words. Ionosphere (Auroral ionosphere; Ionospheremagnetosphere interactions; Particle precipitation)

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Application of laser remote sensing technology and super continuous spectrum laser

E3S Web of Conferences ◽

10.1051/e3sconf/202016503002 ◽

2020 ◽

Vol 165 ◽

pp. 03002

Author(s):

Li Jing ◽

Che Ying ◽

Jin Meishan ◽

Zhai Yannan ◽

Ding Changhong

Keyword(s):

Remote Sensing ◽

Continuous Spectrum ◽

Oil Spill ◽

Three Dimensional ◽

High Energy ◽

High Energy Density ◽

Laser Radar ◽

Laser Source ◽

Spectral Information ◽

Distant Target

Fiber optic super continuous spectrum laser technology is a new technology developed in recent years. It takes into account the advantages of good alignment of laser source, high energy density and wide wavelength range of ordinary white light source, which can not only accurately remote sense distant target, but also obtain hyperspectral information of distant target. Super continuous spectrum of laser radar is a kind of remote sensing monitoring instrument, it can obtain three-dimensional spectral information of the target, and can be accurately detected in the night of distant high spectral information, the all-weather, three-dimensional spectrum detection method with the traditional passive remote sensing compared with single/multiband laser radar technology has incomparable advantages. Based on the development trend of lidar abroad, the development status of super-continuous spectrum lidar in China and the problems in remote sensing detection of oil spill, this paper introduces the feasibility of using super-continuous spectrum laser to monitor oil spill in the sea, which lays a foundation for further research.

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