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

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.

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

Annales Geophysicae ◽

10.5194/angeo-30-1611-2012 ◽

2012 ◽

Vol 30 (11) ◽

pp. 1611-1621 ◽

Cited By ~ 6

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

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

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-1553-2012 ◽

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.

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-4415-2006 ◽

2006 ◽

Vol 6 (12) ◽

pp. 4415-4426 ◽

Cited By ~ 56

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.

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-4387-2012 ◽

2012 ◽

Vol 12 (10) ◽

pp. 4387-4398 ◽

Cited By ~ 32

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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Sensitivity of meteoric smoke distribution to microphysical properties and atmospheric conditions

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-5357-2006 ◽

2006 ◽

Vol 6 (3) ◽

pp. 5357-5386 ◽

Cited By ~ 1

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 atmopsphere 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.

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Development of the mesospheric Na layer at 69° N during the Geminids meteor shower 2010

Annales Geophysicae ◽

10.5194/angeo-31-61-2013 ◽

2013 ◽

Vol 31 (1) ◽

pp. 61-73 ◽

Cited By ~ 14

Author(s):

T. Dunker ◽

U.-P. Hoppe ◽

G. Stober ◽

M. Rapp

Keyword(s):

Column Density ◽

Meteor Shower ◽

Sounding Rocket ◽

Line Of Sight ◽

Number Density ◽

Sodium Layer ◽

Meteoric Smoke ◽

Meteor Trails ◽

Sporadic Meteors

Abstract. The ECOMA sounding rocket campaign in 2010 was performed to investigate the charge state and number density of meteoric smoke particles during the Geminids meteor shower in December 2010. The ALOMAR Na lidar contributed to the campaign with measurements of sodium number density, temperature and line-of-sight wind between 80 and 110 km altitude over Andøya in northern Norway. This paper investigates a possible connection between the Geminids meteor shower and the mesospheric sodium layer. We compare with data from a meteor radar and from a rocket-borne in situ particle instrument on three days. Our main result is that the sodium column density is smaller during the Geminids meteor shower than the winter average at the same latitude. Moreover, during two of the three years considered, the sodium column density decreased steadily during these three weeks of the year. Both the observed decrease of Na column density by 30% and of meteoric smoke particle column density correlate well with a corresponding decrease of sporadic meteor echoes. We found no correlation between Geminids meteor flux rates and sodium column density, nor between sporadic meteors and Na column density (R = 0.25). In general, we found the Na column density to be at very low values for winter, between 1.8 and 2.6 × 1013 m−2. We detected two meteor trails containing sodium, on 13 December 2010 at 87.1 km and on 19 December 2010 at 84 km. From these meteor trails, we estimate a global meteoric Na flux of 121 kg d−1 and a global total meteoric influx of 20.2 t d−1.

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