PMWE creation mechanism inferred from sounding rocket measurements

2021 ◽  
Author(s):  
Boris Strelnikov ◽  
Keyword(s):  
Electron Density ◽  
Current Knowledge ◽  
Sounding Rocket ◽  
Small Scale ◽  
Sounding Rockets ◽  
Smoke Particles ◽  
The North ◽  
Air Turbulence ◽  
Rocket Measurements

<p>A first sounding rocket campaign dedicated to investigate the creation mechanism of Polar Mesosphere Winter Echoes (PMWE) was conducted in April 2018 from the north Norwegian Andøya Space Center (69°N, 16°E). Two instrumented sounding rockets were launched on 13th and 18th of April under PMWE and no-PMWE conditions, respectively.</p><p>In this paper we give a brief summary of our current knowledge of PMWE and an overview of the PMWE sounding rocket mission. We describe and discuss some results of combined in situ and ground-based measurements which allow <span>to</span> <span>check</span> the existing PMWE theories.</p><p>Our measurements clearly show that the coherent structures in refractive index variations (forming PMWE) are accompanied by neutral air turbulence, which is reflected in small-scale structures (down to some meters) of neutral and electron density. We show that the behavior of the structures under investigation together with the atmospheric background is consistent with the interpretation, that PMWE were created by turbulence. Rocket measurements ultimately show that polar winter mesosphere is abounded with meteor smoke particles (MSP) and intermittent turbulent layers. Furthermore, it becomes clear that charged Meteor Smoke Particles (MSP) and background electron density can only enhance SNR, while turbulence is a prerequisite for their formation.</p>

scholarly journals Signatures of mesospheric particles in ionospheric data

2009 ◽  
Vol 27 (2) ◽  
pp. 823-829 ◽  
Author(s):  
M. Friedrich ◽  
K. M. Torkar ◽  
W. Singer ◽  
I. Strelnikova ◽  
M. Rapp ◽  
...  
Keyword(s):  
Electron Density ◽  
Indirect Evidence ◽  
Meteor Radar ◽  
Sounding Rockets ◽  
Close Vicinity ◽  
Incoherent Scatter ◽  
Summer Echoes ◽  
In Situ Observations ◽  
Mf Radar

Abstract. The state of the ionosphere during the 2007 ECOMA/MASS campaign is described by in-situ observations by three sounding rockets launched from the Andøya Rocket Range and by ground based observations. The ground based measurements included the incoherent scatter radar EISCAT near Tromsø (both on UHF and VHF), as well as an MF radar, a meteor radar and an imaging riometer all located in the close vicinity of the rocket range. The pronounced electron density bite-outs seen by two of the rockets could not be detected from the ground, but the associated PMSE (Polar Mesospheric Summer Echoes) provide indirect evidence of pronounced perturbations of mesospheric electron densities.

scholarly journals Simultaneous in situ measurements of small-scale structures in neutral, plasma, and atomic oxygen densities during WADIS sounding rocket project

2019 ◽  
Author(s):  
Boris Strelnikov ◽  
Martin Eberhart ◽  
Martin Friedrich ◽  
Jonas Hedin ◽  
Mikhail Khaplanov ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Atomic Oxygen ◽  
Density Fluctuations ◽  
Sounding Rocket ◽  
Small Scale ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Mlt Region ◽  
Diffusion Properties

Abstract. In this paper we present an overview of measurements conducted during the WADIS-2 rocket campaign. We investigate the effect of small-scale processes like gravity waves and turbulence on the distribution of atomic oxygen and other species in the MLT region. Our analysis suggests that density fluctuations of atomic oxygen are coupled to fluctuations of other constituents, i.e., plasma and neutrals. Our measurements show that all measured quantities, including winds, densities, and temperatures, reveal signatures of both waves and turbulence. We show observations of gravity wave saturation and breakdown together with simultaneous measurements of generated turbulence. Atomic oxygen inside turbulence layers shows two different spectral behaviors, which might imply change of its diffusion properties.

Auroral electrodynamics---investigation by a dual sounding rocket experiment

2020 ◽  
Author(s):  
Hassanali Akbari ◽  
Robert Pfaff ◽  
Keyword(s):  
Electric Fields ◽  
Sounding Rocket ◽  
Sounding Rockets ◽  
Neutral Winds ◽  
Incoherent Scatter ◽  
Ac Electric Fields ◽  
Numerical Studies ◽  
Rocket Experiment ◽  
N Wave

<p>We present results from a 2017 sounding rocket experiment in which two NASA sounding rockets were simultaneously launched into the auroral ionosphere. The rockets included comprehensive instrumentation to measure DC and AC electric fields, magnetic fields, energetic particles, plasma density, and neutral winds, among other parameters, and achieved apogees of 190 and 330 km. This unprecedented collection of in-situ measurements obtained at two altitudes over an auroral arc, along with conjugate ground-based measurements by the Poker Flat incoherent scatter radar and all-sky cameras, enable us to investigate the behavior of an aurora arc and its associated electrodynamics. A prominent feature of our observations is the presence of localized, large-amplitude Alfvén wave structures observed in both the electric field and magnetometers at altitudes as low as 190 km in the vicinity of up- and down-ward current regions. The observations are discussed in the context of ionospheric feedback instability. The results are compared to predictions of previously published numerical studies and other sounding rocket observations.</p>

scholarly journals Feasibility Study and Demonstration of an Aluminum and Ice Solid Propellant

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Timothee L. Pourpoint ◽  
Tyler D. Wood ◽  
Mark A. Pfeil ◽  
John Tsohas ◽  
Steven F. Son
Keyword(s):  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Sounding Rocket ◽  
Small Scale ◽  
Solid Propellants ◽  
Aluminum Particles ◽  
Underwater Propulsion ◽  
Binary Formulation

Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micron-sized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles.

scholarly journals Multi-scale measurements of mesospheric aerosols and electrons during the MAXIDUSTY campaign

2019 ◽  
Vol 12 (4) ◽  
pp. 2139-2153
Author(s):  
Tarjei Antonsen ◽  
Ove Havnes ◽  
Andres Spicher
Keyword(s):  
Cloud System ◽  
Sounding Rocket ◽  
Small Scale ◽  
Plasma Parameters ◽  
Multi Scale ◽  
System A ◽  
Power Spectral ◽  
Good Agreement ◽  
Strong Spin

Abstract. We present in situ measurements of small-scale fluctuations in aerosol populations as recorded through a mesospheric cloud system from the Faraday cups DUSTY and MUDD during on the MAXIDUSTY-1 and 1B sounding rocket payloads launched in the summer of 2016. Two mechanically identical DUSTY probes mounted with an inter-spacing of ∼10 cm recorded very different currents, with strong spin modulation, in certain regions of the cloud system. A comparison to auxiliary measurement show similar tendencies in the MUDD data. Fluctuations in the electron density are found to be generally anti-correlated to the negative aerosol charge density on all length scales; however, in certain smaller regions the correlation turns positive. We have also compared the spectral properties of the dust fluctuations, as extracted by wavelet analysis, to polar mesospheric summer echo (PMSE) strength. In this analysis, we find a relatively good agreement between the power spectral density (PSD) at the radar Bragg scale inside the cloud system; however the PMSE edge is not well represented by the PSD. A comparison of proxies for PMSE strength, constructed from a combination of derived dusty plasma parameters, shows that no simple proxy can reproduce PMSE strength well throughout the cloud system. Edge effects are especially poorly represented by the proxies addressed here.

GEOTECHNICAL ASPECTS OF FOUNDATION INVESTIGATIONS FOR PRODUCTION PLATFORMS AT NORTH RANKIN

1980 ◽  
Vol 20 (1) ◽  
pp. 257
Author(s):  
R.W. King
Keyword(s):  
Load Test ◽  
Small Scale ◽  
Foundation Design ◽  
The North ◽  
Limited Experience ◽  
Load Tests ◽  
Definition Of ◽  
Petroleum Development ◽  
First Time

Production platforms required for the development of the North Rankin gas/condensate field will be founded on deep deposits of loose to weakly cemented calcareous material of predominantly marine origin. Although the data base for foundation design in these materials is extremely limited, experience has shown that calcareous sediments exhibit unusual engineering characteristics and that in situ load tests appear to be the most reliable indicator of soil-bearing potential.The foundation investigations performed at North Rankin, in 1978, integrated conventional soil sampling techniques with cone penetrometer testing (CPT), which is a small-scale load test that provides a semicontinuous profile of soil resistance. This being the first time that CPT had been used extensively in calcareous sediments, a series of innovative prototype in situ load tests were performed to provide data for calibration of the core resistance profile.A modified carbonate classification system was introduced into the programme and, together with detailed geological analysis of specimens, it provided an insight into subtle variations in lithology and cementation throughout the profile.These new developments and the comprehensive nature of the investigation produced a large amount of data that are relevant to other locations where similar sediments exist.As a result of these investigations and subsequent studies, Woodside Petroleum Development has been able to progress confidently in the definition of a suitable foundation system and the design of the North Rankin platforms.

scholarly journals Estimate of size distribution of charged MSPs measured in situ in winter during the WADIS-2 sounding rocket campaign

2017 ◽  
Vol 35 (4) ◽  
pp. 979-998 ◽  
Author(s):  
Heiner Asmus ◽  
Tristan Staszak ◽  
Boris Strelnikov ◽  
Franz-Josef Lübken ◽  
Martin Friedrich ◽  
...  
Keyword(s):  
Size Distribution ◽  
Lower Thermosphere ◽  
Size Distribution Function ◽  
Density Fluctuations ◽  
Sounding Rocket ◽  
Turbulence Energy ◽  
Distribution Width ◽  
Smoke Particles ◽  
Schmidt Numbers

Abstract. We present results of in situ measurements of mesosphere–lower thermosphere dusty-plasma densities including electrons, positive ions and charged aerosols conducted during the WADIS-2 sounding rocket campaign. The neutral air density was also measured, allowing for robust derivation of turbulence energy dissipation rates. A unique feature of these measurements is that they were done in a true common volume and with high spatial resolution. This allows for a reliable derivation of mean sizes and a size distribution function for the charged meteor smoke particles (MSPs). The mean particle radius derived from Schmidt numbers obtained from electron density fluctuations was ∼ 0.56 nm. We assumed a lognormal size distribution of the charged meteor smoke particles and derived the distribution width of 1.66 based on in situ-measured densities of different plasma constituents. We found that layers of enhanced meteor smoke particles' density measured by the particle detector coincide with enhanced Schmidt numbers obtained from the electron and neutral density fluctuations. Thus, we found that large particles with sizes  > 1 nm were stratified in layers of  ∼ 1 km thickness and lying some kilometers apart from each other.

scholarly journals Large- to submesoscale surface circulation and its implications on biogeochemical/biological horizontal distributions during the OUTPACE cruise (southwest Pacific)

2018 ◽  
Vol 15 (8) ◽  
pp. 2411-2431 ◽  
Author(s):  
Louise Rousselet ◽  
Alain de Verneil ◽  
Andrea M. Doglioli ◽  
Anne A. Petrenko ◽  
Solange Duhamel ◽  
...  
Keyword(s):  
Large Scale ◽  
Water Mass ◽  
Finite Size ◽  
Small Scale ◽  
General Direction ◽  
The North ◽  
Mesoscale Structures ◽  
Surface Circulation ◽  
Biogeochemical Parameters

Abstract. The patterns of the large-scale, meso- and submesoscale surface circulation on biogeochemical and biological distributions are examined in the western tropical South Pacific (WTSP) in the context of the OUTPACE cruise (February–April 2015). Multi-disciplinary original in situ observations were achieved along a zonal transect through the WTSP and their analysis was coupled with satellite data. The use of Lagrangian diagnostics allows for the identification of water mass pathways, mesoscale structures, and submesoscale features such as fronts. In particular, we confirmed the existence of a global wind-driven southward circulation of surface waters in the entire WTSP, using a new high-resolution altimetry-derived product, validated by in situ drifters, that includes cyclogeostrophy and Ekman components with geostrophy. The mesoscale activity is shown to be responsible for counter-intuitive water mass trajectories in two subregions: (i) the Coral Sea, with surface exchanges between the North Vanuatu Jet and the North Caledonian Jet, and (ii) around 170∘ W, with an eastward pathway, whereas a westward general direction dominates. Fronts and small-scale features, detected with finite-size Lyapunov exponents (FSLEs), are correlated with 25 % of surface tracer gradients, which reveals the significance of such structures in the generation of submesoscale surface gradients. Additionally, two high-frequency sampling transects of biogeochemical parameters and microorganism abundances demonstrate the influence of fronts in controlling the spatial distribution of bacteria and phytoplankton, and as a consequence the microbial community structure. All circulation scales play an important role that has to be taken into account not only when analysing the data from OUTPACE but also, more generally, for understanding the global distribution of biogeochemical components.

scholarly journals Daily to annual net primary production in the North Sea determined using autonomous underwater gliders and satellite Earth observation

2021 ◽  
Author(s):  
Benjamin Loveday ◽  
Timothy Smyth ◽  
Anıl Akpinar ◽  
Tom Hull ◽  
Mark Inall ◽  
...  
Keyword(s):  
Time Series ◽  
Primary Production ◽  
North Sea ◽  
Large Scale ◽  
Net Primary Production ◽  
Earth Observation ◽  
Small Scale ◽  
The North ◽  
The North Sea

Abstract. Shelf-seas play a key role in both the global carbon cycle and coastal marine ecosystems through the drawn-down and fixing of carbon, as measured through phytoplankton net primary production (NPP). Measuring NPP in situ, and extrapolating this to the local, regional and global scale presents challenges however because of limitations with the techniques utilised (e.g. radiocarbon isotopes), data sparsity and the inherent biogeochemical heterogeneity of coastal and open-shelf waters. Here, we introduce a powerful new technique based on the synergistic use of in situ glider profiles and satellite Earth Observation measurements which can be implemented in a real-time or delayed mode system. We apply this system to a fleet of gliders successively deployed over a 19-month time-frame in the North Sea, generating an unprecedented fine scale time-series of NPP in the region (Loveday and Smyth, 2020). At the large-scale, this time-series gives close agreement with existing satellite-based estimates of NPP for the region and previous in situ estimates. What has not been elucidated before is the high-frequency, small-scale, depth-resolved variability associated with bloom phenology, mesoscale phenomena and mixed layer dynamics.

scholarly journals Large to submesoscale surface circulation and its implications on biogeochemical/biological horizontal distributions during the OUTPACE cruise (SouthWest Pacific)

2017 ◽  
Author(s):  
Louise Rousselet ◽  
Alain de Verneil ◽  
Andrea M. Doglioli ◽  
Anne A. Petrenko ◽  
Solange Duhamel ◽  
...  
Keyword(s):  
Large Scale ◽  
Water Mass ◽  
Finite Size ◽  
Small Scale ◽  
General Direction ◽  
The North ◽  
Mesoscale Structures ◽  
Surface Circulation ◽  
Biogeochemical Parameters

Abstract. The patterns of the large-scale, meso- and submesoscale surface circulation on biogeochemical and biological distributions are examined in the Western Tropical South Pacific (WTSP) in the context of the OUTPACE cruise (Feb–April 2015). Multi-disciplinary original in situ observations were achieved along a zonal transect through the WTSP and their analysis was coupled with satellite data. The use of Lagrangian diagnostics allows for the identification of water mass pathways, mesoscale structures, and submesoscale features such as fronts. In particular, we confirmed the existence of a global wind-driven southward circulation of surface waters in the entire WTSP, using a new high-resolution altimetry-derived product, validated by in situ drifters, that includes cyclogeostrophy and Ekman components with geostrophy. Two subregions show counter-intuitive water mass trajectories due to mesoscale circulation: i) the Coral Sea with surface exchanges between the North Vanuatu Jet and the North Caledonian Jet; and ii) the zonal band between 180° W and 170° W with an eastward propagation whereas a westward general direction dominates. Fronts and small-scale features, detected with Finite-Size Lyapunov Exponents (FSLE), are correlated with 25 % of surface tracer gradients which reveals the significance of such structures in the generation of submesoscale surface gradients. Additionally, two high-frequency sampling transects of biogeochemical parameters and micro-organism abundances demonstrate the influence of fronts in controlling the spatial distribution of bacteria and phytoplankton, and as a consequence the microbial community structure. All circulation scales play an important role that has to be taken into account when analysing the data from OUTPACE but also, more generally, to understand the global distribution of biogeochemical components.

Sign in / Sign up

Export Citation Format

Share Document