scholarly journals Observations of NO in the upper mesosphere and lower thermosphere during ECOMA 2010

2012 ◽  
Vol 30 (11) ◽  
pp. 1611-1621 ◽  
Author(s):  
J. Hedin ◽  
M. Rapp ◽  
M. Khaplanov ◽  
J. Stegman ◽  
G. Witt
Keyword(s):  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Meteor Shower ◽  
The Other ◽  
Sounding Rocket ◽  
Northern Norway ◽  
Smoke Particles ◽  
Meteoric Smoke ◽  
Mesosphere And Lower Thermosphere ◽  
Main Instrument

Abstract. In December 2010 the last campaign of the German-Norwegian sounding rocket project ECOMA (Existence and Charge state Of Meteoric smoke particles in the middle Atmosphere) was conducted from Andøya Rocket Range in northern Norway (69° N, 16° E) in connection with the Geminid meteor shower. The main instrument on board the rocket payloads was the ECOMA detector for studying meteoric smoke particles (MSPs) by active photoionization and subsequent detection of the produced charges (particles and photoelectrons). In addition to photoionizing MSPs, the energy of the emitted photons from the ECOMA flash-lamp is high enough to also photoionize nitric oxide (NO). Thus, around the peak of the NO layer, at and above the main MSP layer, photoelectrons produced by the photoionization of NO are expected to contribute to, or even dominate above the main MSP-layer, the total measured photoelectron current. Among the other instruments on board was a set of two photometers to study the O2 (b1Σg+−X3Σg

scholarly journals The Geminid meteor shower during the ECOMA sounding rocket campaign: specular and head echo radar observations

2013 ◽  
Vol 31 (3) ◽  
pp. 473-487 ◽  
Author(s):  
G. Stober ◽  
C. Schult ◽  
C. Baumann ◽  
R. Latteck ◽  
M. Rapp
Keyword(s):  
Middle Atmosphere ◽  
Meteor Shower ◽  
Sounding Rocket ◽  
Radar Observations ◽  
Smoke Particles ◽  
Meteor Flux ◽  
Launch Site ◽  
Meteoric Smoke ◽  
Head Echo ◽  
Echo Radar

Abstract. The ECOMA (Existence of Charge state Of meteoric smoke particles in the Middle Atmosphere) sounding rocket campaign was conducted during the Geminid meteor shower in December 2010 in order to explore whether there is a change of the properties of meteoric smoke particles due to the stream. In parallel to the rocket flights, three radars monitored the Geminid activity located at the launch site in Northern Norway and in Northern Germany to gain information about the meteor flux into the atmosphere. The results presented here are based on specular meteor radar observations measuring the radiant position, the velocity and the meteor flux into the atmosphere during the Geminids. Further, the MAARSY (Middle Atmosphere Alomar Radar System) radar was operated to conduct meteor head echo experiments. The interferometric capabilities of MAARSY permit measuring the meteor trajectories within the radar beam and to determine the source radiant and geocentric meteor velocity, as well as to compute the meteor orbit.

scholarly journals The influence of surface charge on the coalescence of ice and dust particles in the mesosphere and lower thermosphere

2021 ◽  
Vol 21 (11) ◽  
pp. 8735-8745
Author(s):  
Joshua Baptiste ◽  
Connor Williamson ◽  
John Fox ◽  
Anthony J. Stace ◽  
Muhammad Hassan ◽  
...  
Keyword(s):  
Surface Charge ◽  
Lower Thermosphere ◽  
Coefficient Of Restitution ◽  
Dust Particles ◽  
Opposite Charge ◽  
Smoke Particles ◽  
Meteoric Smoke ◽  
Relative Kinetic ◽  
Mesosphere And Lower Thermosphere ◽  
Small Separation

Abstract. Agglomeration of charged ice and dust particles in the mesosphere and lower thermosphere is studied using a classical electrostatic approach, which is extended to capture the induced polarisation of surface charge. Collision outcomes are predicted whilst varying the particle size, charge, dielectric constant, relative kinetic energy, collision geometry and the coefficient of restitution. In addition to Coulomb forces acting on particles of opposite charge, instances of attraction between particles of the same sign of charge are discussed. These attractive forces are governed by the polarisation of surface charge and can be strong at very small separation distances. In the mesosphere and lower thermosphere, these interactions could also contribute to the formation of stable aggregates and contamination of ice particles through collisions with meteoric smoke particles.

scholarly journals Large-Scale Waves in the Mesosphere and Lower Thermosphere Observed by SABER

2005 ◽  
Vol 62 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Rolando R. Garcia ◽  
Ruth Lieberman ◽  
James M. Russell ◽  
Martin G. Mlynczak
Keyword(s):  
Large Scale ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Normal Modes ◽  
Zonal Winds ◽  
Broadband Emission ◽  
Summer Hemisphere ◽  
Mean Structure ◽  
Mesosphere And Lower Thermosphere ◽  
The Tropics

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.

scholarly journals Interactions of meteoric smoke particles with sulphuric acid in the Earth's stratosphere

2012 ◽  
Vol 12 (1) ◽  
pp. 1553-1584
Author(s):  
R. W. Saunders ◽  
S. Dhomse ◽  
W. S. Tian ◽  
M. P. Chipperfield ◽  
J. M. C. Plane
Keyword(s):  
Sulphuric Acid ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Magnesium Silicate ◽  
Stratospheric Aerosol ◽  
Solution Viscosity ◽  
Time Resolved ◽  
Optical Extinction ◽  
Smoke Particles ◽  
Meteoric Smoke

Abstract. Nano-sized meteoric smoke particles (MSPs) with iron-magnesium silicate compositions, formed in the upper mesosphere as a result of meteoric ablation, may remove sulphuric acid from the gas-phase above 40 km and may also affect the composition and behaviour of supercooled H2SO4-H2O droplets in the global stratospheric aerosol (Junge) layer. This study describes a time-resolved spectroscopic analysis of the evolution of the ferric (Fe3+) ion originating from amorphous ferrous (Fe2+)-based silicate powders dissolved in varying Wt % sulphuric acid (30–75%) solutions over a temperature range of 223–295 K. Complete dissolution of the particles was observed under all conditions. The first-order rate coefficient for dissolution decreases at higher Wt % and lower temperature, which is consistent with the increased solution viscosity limiting diffusion of H2SO4 to the particle surfaces. Dissolution under stratospheric conditions should take less than a week, and is much faster than the dissolution of crystalline Fe2+ compounds. The chemistry climate model UMSLIMCAT (based on the UKMO Unified Model) was then used to study the transport of MSPs through the middle atmosphere. A series of model experiments were performed with different uptake coefficients. Setting the concentration of 1.5 nm radius MSPs at 80 km to 3000 cm−3 (based on rocket-borne charged particle measurements), the model matches the reported Wt % Fe values of 0.5–1.0 in Junge layer sulphate particles, and the MSP optical extinction between 40 and 75 km measured by a satellite-borne spectrometer, if the global meteoric input rate is about 20 t d−1. The model indicates that an uptake coefficient ≥0.01 is required to account for the observed two orders of magnitude depletion of H2SO4 vapour above 40 km.

scholarly journals Global change induced trends in ion composition of the troposphere to the lower thermosphere

2008 ◽  
Vol 26 (5) ◽  
pp. 1181-1187 ◽  
Author(s):  
G. Beig
Keyword(s):  
Middle Atmosphere ◽  
Anthropogenic Activities ◽  
Lower Thermosphere ◽  
Cluster Ions ◽  
Atmospheric Density ◽  
Mesosphere And Lower Thermosphere ◽  
Induced Changes ◽  
Positive Ion ◽  
Mlt Region

Abstract. In this paper a brief overview of the changes in atmospheric ion compositions driven by the human-induced changes in related neutral species, and temperature from the troposphere to lower thermosphere has been made. It is found that ionic compositions undergo significant variations. The variations calculated for the double-CO2 scenario are both long-term and permanent in nature. Major neutrals which take part in the lower and middle atmospheric ion chemical schemes and undergo significant changes due to anthropogenic activities are: O, O2, H2O, NO, acetonitrile, pyridinated compounds, acetone and aerosol. The concentration of positive ion/electron density does not change appreciably in the middle atmosphere but indicates a marginal decrease above about 75 km until about 85 km, above which the magnitude of negative trend decreases and becomes negligible at 93 km. Acetonitrile cluster ions in the upper stratosphere are likely to increase, whereas NO+ and NO+(H2O) in the mesosphere and lower thermosphere (MLT) region are expected to decrease for the double CO2 scenario. It is also found that the atmospheric density of pyridinated cluster ions is fast rising in the troposphere.

scholarly journals Distribution of meteoric smoke – sensitivity to microphysical properties and atmospheric conditions

2006 ◽  
Vol 6 (12) ◽  
pp. 4415-4426 ◽  
Author(s):  
L. Megner ◽  
M. Rapp ◽  
J. Gumbel
Keyword(s):  
Middle Atmosphere ◽  
Mass Density ◽  
Temporal Variations ◽  
Vertical Wind ◽  
Noctilucent Clouds ◽  
Atmospheric Conditions ◽  
Smoke Particles ◽  
Microphysical Properties ◽  
Meteoric Smoke ◽  
Atmospheric Phenomena

Abstract. Meteoroids entering the Earth's atmosphere experience strong deceleration and ablate, whereupon the resulting material is believed to re-condense to nanometre-size "smoke particles". These particles are thought to be of great importance for many middle atmosphere phenomena, such as noctilucent clouds, polar mesospheric summer echoes, metal layers, and heterogeneous chemistry. The properties and distribution of meteoric smoke depend on poorly known or highly variable factors such as the amount, composition and velocity of incoming meteoric material, the efficiency of coagulation, and the state and circulation of the atmosphere. This work uses a one-dimensional microphysical model to investigate the sensitivities of meteoric smoke properties to these poorly known or highly variable factors. The resulting uncertainty or variability of meteoric smoke quantities such as number density, mass density, and size distribution are determined. It is found that the two most important factors are the efficiency of the coagulation and background vertical wind. The seasonal variation of the vertical wind in the mesosphere implies strong global and temporal variations in the meteoric smoke distribution. This contrasts the simplistic picture of a homogeneous global meteoric smoke layer, which is currently assumed in many studies of middle atmospheric phenomena. In particular, our results suggest a very low number of nanometre-sized smoke particles at the summer mesopause where they are thought to serve as condensation nuclei for noctilucent clouds.

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 Interactions of meteoric smoke particles with sulphuric acid in the Earth's stratosphere

2012 ◽  
Vol 12 (10) ◽  
pp. 4387-4398 ◽  
Author(s):  
R. W. Saunders ◽  
S. Dhomse ◽  
W. S. Tian ◽  
M. P. Chipperfield ◽  
J. M. C. Plane
Keyword(s):  
Sulphuric Acid ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Magnesium Silicate ◽  
Stratospheric Aerosol ◽  
Solution Viscosity ◽  
Time Resolved ◽  
Optical Extinction ◽  
Smoke Particles ◽  
Meteoric Smoke

Abstract. Nano-sized meteoric smoke particles (MSPs) with iron-magnesium silicate compositions, formed in the upper mesosphere as a result of meteoric ablation, may remove sulphuric acid from the gas-phase above 40 km and may also affect the composition and behaviour of supercooled H2SO4-H2O droplets in the global stratospheric aerosol (Junge) layer. This study describes a time-resolved spectroscopic analysis of the evolution of the ferric (Fe3+) ion originating from amorphous ferrous (Fe2+)-based silicate powders dissolved in varying Wt % sulphuric acid (30–75 %) solutions over a temperature range of 223–295 K. Complete dissolution of the particles was observed under all conditions. The first-order rate coefficient for dissolution decreases at higher Wt % and lower temperature, which is consistent with the increased solution viscosity limiting diffusion of H2SO4 to the particle surfaces. Dissolution under stratospheric conditions should take less than a week, and is much faster than the dissolution of crystalline Fe2+ compounds. The chemistry climate model UMSLIMCAT (based on the UKMO Unified Model) was then used to study the transport of MSPs through the middle atmosphere. A series of model experiments were performed with different uptake coefficients. Setting the concentration of 1.5 nm radius MSPs at 80 km to 3000 cm−3 (based on rocket-borne charged particle measurements), the model matches the reported Wt % Fe values of 0.5–1.0 in Junge layer sulphate particles, and the MSP optical extinction between 40 and 75 km measured by a satellite-borne spectrometer, if the global meteoric input rate is about 20 tonnes per day. The model indicates that an uptake coefficient ≥0.01 is required to account for the observed two orders of magnitude depletion of H2SO4 vapour above 40 km.

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