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<p>You probably have seen <strong>shooting stars</strong> in
the night sky. But have you ever wondered what happens to all
this material "burning up" in the atmosphere...?</p>
<p>The MAGIC project has been designed to study this great
mystery of the Earth's upper atmosphere. The MAGIC rocket will
be launched from Esrange, Sweden, in January 2005. It will
take scientific instruments to a height of about 100 km.
During the flight, we will attempt to <strong>collect the
meteoric material</strong> in the atmosphere and to return it
to the ground. After the flight everything will be taken to
laboratories where various methods will be applied to analyze
the collected "stardust".</p>
<p>The acronym <strong>"MAGIC"</strong> stands for the aims of
this project: <b>M</b>esospheric <b>A</b>erosol -
<b>G</b>enesis, <b>I</b>nteraction and <b>C</b>omposition.</p>
<h2>Meteorites, Smoke and Magic Dust...</h2>
<p>In fact, about <strong>100 tons of meteoric
material</strong> enter the Earth's atmosphere every day. Most
of it comes in the form of small meteoroid particles with
sizes smaller than 1 mm. These particles come with typical
speeds of 10-20 km/s. Collisions with air molecules heat the
particles to temperatures high enough to vaporise them. This
happens at heights between 70 and 100 km, in a part of the
atmosphere that is known as the <strong>mesosphere</strong>.
During this evaporation process larger particles can glow so
brightly that they become visible from the ground as shooting
stars.</p>
<p>Meteroid particles consist mainly of metals like iron,
silicon, potassium, sodium and various oxides. Thus, the
evaporated material forms <strong>metal layers</strong> in the
upper mesosphere. These layers are well known and can be
observed with ground-based instruments like lidars. However,
when it comes to the further fate of this material, we simply
do not know very much...</p>
<p>There are some ideas based on theoretical considerations:
It is generally assumed that the metallic material condenses
within a few days to form tiny particles with a radius of only
a few nanometers (1 nanometer = 1 millionth millimeter). These
recondensed particles are commonly called <strong>smoke
particles</strong>. They are assumed to follow the general
motion (advection) of the air. Sooner or later this motion can
transport the smoke particles down to the lower atmosphere
where they can be taken up by clouds and finally rain out of
the atmosphere.</p>
<p>It has also been suggested that these smoke particles play
an important role for many atmospheric processes. As an
example, they could provide condensation nuclei for the growth
of ice particles that form <strong>noctilucent clouds</strong>
in the mesosphere. Noctilucent clouds are by far the highest
clouds that we know about the atmosphere. They occur at
heights around 82 km, but only during summer and only at high
latitudes. During summer twilight conditions they can become
visible as bright structures in the night sky. The photo below
shows an example: Noctilucent clouds observed above Stockholm.
(Photo by N. Wilhelm)</p>
<p>Other atmospheric processes that smoke particles may be
involved in concern chemistry, charging processes and the
metal budget in the mesosphere. So smoke particles are
potentially very important in the atmosphere.</p>
<p style="text-align: center; margin: 30px 40px 30px 40px;
font-size: 12pt; font-weight: bold; color: #cc0000">But:
Noboby has ever investigated these smoke particles. As a
matter of fact, nobody has ever proven that these particles
really exist.</p>
<p>Because of this lack of knowledge, smoke particles have
been called, less seriously, for <strong>"magic
dust"</strong>. This is where the idea for the MAGIC rocket
project started. We want to find out wether these particles
exist in the mesosphere. And we want to study their
properties.
<h2>Our Scientific Questions</h2>
<ul>
<li>Do smoke particles of cosmic origin exist in the
mesosphere?</li>
<li>How many particles are there as a function of height?</li>
<li>What is the size of these particles?</li>
<li>What are they made of?</li>
<li>How are they charged?</li>
<li>How are these particles transported in the
atmosphere?</li>
</ul>
<h2>The MAGIC Project</h2>
<p>In order to study smoke particles in the mesosphere, we
address several related parameters simultaneously: smoke
particle distribution and properties, atmospheric structure,
transport processes, and charge distribution. The MAGIC
campaign will take place at <strong>Esrange, Sweden, in
January 2005</strong>. It will provide co-ordinated
atmospheric measurements from rockets, balloon, the ground as
well as from the Swedish Odin satellite. (Photo of Esrange by
J. Gumbel)
<p>The MAGIC project is an outstanding example for
<strong>international collaboration</strong> in atmospheric
research. The MAGIC idea was developed at the <a
href="http://spacescience.nrl.navy.mil" target="_top">Naval
Research Laboratory</a> (NRL) in Washington DC, USA. This was
done in close collaboration between U.S., Swedish, and German
scientists. In early 2002, <a href="http://www.nasa.gov"
target="_top">NASA</a> approved and funded the development of
the MAGIC instrumentation. At the same time the <a
href="http://www.misu.su.se" target="_top">Department of
Meteorology at Stockholm University</a> (MISU) proposed a
Swedish rocket campaign to launch the MAGIC instruments from
Esrange. In 2003, the <a
href="http://www.snsb.se/dyn_aktuellt.asp?languageId=2"
target="_top">Swedish National Space Board</a> (SNSB) approved
and funded this campaign.</p>
<p>The research groups involved in the MAGIC campaign and its
analysis are</p>
<table width="95%" align="center" cellspacing="0"
cellspacing="0" border="1" bordercolor="#000000"
bgcolor="#ffffcc">
<tr>
<th width="40%">Research Group</th>
<th width="60%">Responsibility</th>
</td>
<tr>
<td><a href="http://www.misu.su.se" target="_top">Department
of Meteorology at Stockholm University</a> (MISU), Sweden</td>
<td>• scientific coordination of the MAGIC campaign
• measurements of water vapour from rocket and
balloon</td>
</tr>
<tr>
<td><a href="http://spacescience.nrl.navy.mil"
target="_top">Naval Research Laboratory</a> (NRL), Washington
D.C., USA</td>
<td>• MAGIC particle samplers • analysis of
sampled particles by transmission electron microscopy</td>
</tr>
<tr>
<td><a href="http://lasp.colorado.edu"
target="_top">Laboratory for Atmospheric and Space Physics</a>
(LASP), University of Colorado, USA</td>
<td>• detectors for charged particles onboard the MAGIC
payload</td>
</tr>
<tr>
<td><a href="http://www.physik.uni-bonn.de"
target="_top">University of Bonn</a>, Germany, and <a
href="http://www.misu.su.se" target="_top">Department of
Meteorology at Stockholm University</a></td>
<td>• lidar measurements of temperature and
density</td>
</tr>
<tr>
<td><a href="http://www.irf.se" target="_top">Swedish
Institute for Space Physics</a> (IRF), Kiruna, <a
href="http://www.bath.ac.uk/elec-eng/tsar/RRSA/MLT.htm"
target="_top">University of Bath</a>, U.K., and <a
href="http://www.ssc.se" target="_top">Swedish Space
Corporation</a> (SSC)</td>
<td>• radar measurements of mesospheric structures and
winds</td>
</tr>
<tr>
<td><a href="http://www.ssc.se" target="_top">Swedish Space
Corporation</a> and <a href="http://www.dlr.de"
target="_top">German Aerospace Center</a> (DLR)</td>
<td>• meteorological rocket measurements of winds and
turbulence</td>
</tr>
<tr>
<td><a href="http://www.ssc.se" target="_top">Swedish Space
Corporation</a></td>
<td>• ground-based optical, ionospheric and geomagnetic
measurements</td>
</tr>
<tr>
<td><a href="http://www.infn.it/" target="_top">Instituto
Nazionale di Fisica Nucleare</a> (INFN), Gran Sasso,
Italy</td>
<td>• analysis of sampled particles by gamma ray
spectrometry and mass spectrometry</td>
</tr>
<tr>
<td><a href="http://www.uea.ac.uk" target="_top">University
of East Anglia</a>, Norwich, U.K.</td>
<td>• laboratory studies of smoke particles</td>
</tr>
<tr>
<td><a href="http://www.misu.su.se" target="_top">Department
of Meteorology at Stockholm University</a>, <a
href="http://spacescience.nrl.navy.mil" target="_top">Naval
Research Laboratory</a>, and <a href="http://www.uea.ac.uk"
target="_top">University of East Anglia</a></td>
<td>• model studies of smoke particles</td>
</tr>
<tr>
<td><a href="http://www.rss.chalmers.se"
target="_top">Chalmers University</a> and <a
href="http://www.misu.su.se" target="_top">Department of
Meteorology at Stockholm University</a></td>
<td>• measurements of water vapour and temperature by
the Odin satellite</td>
</tr>
</table>
<p>Payload preparations and launch operations at Esrange are
carried out by the <a href="http://www.ssc.se"
target="_top">Swedish Space Corporation</a> (SSC).</p>
<p>The picture above shows tests of the MAGIC rocket payload
at Packforsk in Stockholm. (Photo by J. Gumbel)</p>
<h2>Particle sampling</h2>
<p>Meteoric smoke particles will be collected in the
mesosphere by the newly developed <strong>MAGIC
detectors</strong>. The
collection of nanometer-size particles is difficult. They are
so small that they simply tend to follow the airflow around
the payload rather than reaching instrument surfaces.
Therefore, aerodynamic considerations were of critical
importance when designing the MAGIC experiment. The basic idea
is to make the detection surface small enough to make
aerodynamic influences negligible: The MAGIC sampling surfaces
have a diameter of less than 3 mm and are positioned on long
pins. These pins are extended one by one from the MAGIC
detector box. Three of these boxes will be flown on the MAGIC
payload, each containing 10 pins. The entire instrument with
an extended pin can be seen to the right. (Photo by T.
Waldemarsson)</p>
<p>This detection concept has been tested by extensive <a
href="http://www.misu.su.se/~gumbel/aerodynamics.html"
target="_top">aerodynamic simulations</a>. The diameter of the
pins is of the same order as the mean free path that an air
molecule travels in the mesosphere between collisions with
other molecules. Under these conditions shock fronts disappear
and smoke particles can approach the collection surface
undisturbed.</p>
<p>The MAGIC payload with the collected particles will return
to the ground on a parachute. After recovery, the MAGIC probes
will be transferred to the <strong>laboratories</strong>
involved in the analysis. Transmission Electron Microscopy
(TEM) is the major tool for investigating the smoke particles.
It will serve to determine the number of the particles and
their sizes. By combining TEM with x-ray spectroscopy
techniques the composition of the particles can be determined.
These measurements will be carried out at the <a
href="http://spacescience.nrl.navy.mil" target="_top">Naval
Research Laboratory</a> (NRL).</p>
<p>Additional investigations by gamma ray spectrometry and
highly sensitive mass spectrometry will be carried out at the
<a href="http://www.infn.it/" target="_top">Instituto
Nazionale di Fisica Nucleare</a> in Italy.</p>
<p>The charge properties of the meteoric particles will be
studied by the charged particle detectors from the <a
href="http://lasp.colorado.edu" target="_top">Laboratory for
Atmospheric and Space Physics</a> at the University of
Colorado directly during the MAGIC rocket flight.</p>
<br clear="all">
<h2>Measuring Water, Temperature, Winds, ...</h2>
<p>It is of central importance to investigate how the
atmospheric circulation transports meteoric smoke. To this
end, we will relate the particle distribution to detailed
measurements of <strong>water vapour</strong>. Water vapour
serves as an excellent tracer for mesospheric transport. These
measurements are done using MISU's optical hygrometer
technique. We have applied this
technique earlier both on rockets and balloons, e.g. during
the <a href="hygro2.html">Hygrosonde-2 campaign</a> from
Esrange.</p>
<p>These measurements will be complemented by ground-based
measurements (lidar and radar) and meteorological rockets to
provide information about the background state of the
atmosphere, in particular <strong>temperature</strong>,
<strong>density</strong> and <strong>wind</strong>. Additional
ground-based measurements on Esrange will concern ionospheric
and auroral conditions.</p>
<p>The picture to the left shows the laser beam of the Bonn
University <strong>lidar</strong> that is located at Esrange.
The light that the atmosphere scatteres back from this laser
beam provides us with information about atmospheric density
and temperature. (Photo by J. Hedin)</p>
<br clear="all" />
<h2>Modelling Studies</h2>
<p>In support of the MAGIC project, also a number of modeling
studies will be performed. These studies concern all phases of
<strong>meteoric particle evolution</strong> from ablation of
meteorites to the global transport of smoke in the mesosphere.
Institutes involved in these studies are <a
href="http://www.misu.su.se" target="_top">MISU</a>, the <a
href="http://spacescience.nrl.navy.mil" target="_top">Naval
Research Laboratory</a> and the <a href="http://www.uea.ac.uk"
target="_top">University of East Anglia</a>. The University of
East Anglia is also heavily involved in laboratory studies
related to smoke particles.</p>
<h2>MAGIC and the Odin Satellite</h2>
<pThe MAGIC campaign is
closely related to another Swedish space project: the <a
href="http://www.snsb.se/eng_odin_intro.shtml"
target="_top">Odin satellite</a>. The launch of the MAGIC
rocket from Esrange will be coordinated with an
<strong>overpass</strong> of Odin. With its unique
capabilities to measure water vapour and temperature in the
mesosphere, Odin is a perfect complement to the aims of MAGIC.
The same idea was applied during the <a
href="hygro2.html">Hygrosonde-2 campaign</a> in 2001, when
valuable conclusions could be drawn from combining the large
scale Odin data with local rocket and balloon
measurements.</p>
<p>As a matter of fact, Odin is connected to the scientific
questions of MAGIC in many ways. A major objective of Odin in
the mesosphere is the detailed study of <strong>noctilucent
clouds</strong> that are thought to depend on the presence of
smoke particles as condensation nuclei. Odin also performs
optical measurements of several <strong>metals</strong> that
are the product of meteor ablation in the mesosphere. The
figure below shows an example: The points represent Odin
measurements of the column density of sodium atoms over the
Northern Hemisphere in April 2003.</p>
<h2>The Future</h2>
<p>Further applications of the MAGIC experiments are already
being planned. The MAGIC experiment is a light-weight, self-
contained instrument that can readily be incorporated into a
variety of different rocket payloads In March 2005, a rocket
from NASA's launch site at <a href="http://www.wff.nasa.gov"
target="_top">Wallops Island</a> will carry a MAGIC detector.
This will provide valuable mid-latitude data complementary to
the Esrange flight.</p>
<p>Important future measurements of meteoric smoke will
concern the summer mesosphere at high latitudes such as
Esrange. Summer is the time for <strong>noctilucent
clouds</strong>. Of course, it would be extremely interesting
to launch rockets with MAGIC detectors and other instruments
into these clouds. Remember that meteoric smoke particles are
thought to be necessary as condensation nuclei for noctilucent
clouds.</p>
<p>Other MAGIC applications concern meteoric smoke
measurements at lower latitudes. Here possible influences of
the particles on <strong>mesospheric chemistry</strong> are
expected to be largest. Measurement of atomic oxygen and other
reactive species would be a natural complement for such
chemical studies.</p>
<h2>Further Reading</h2>
<h3>about meteoric material in the atmosphere:</h3>
<ul>
<li>Ceplecha et al., Meteor phenomena and bodies, <i>Space
Sci. Rev., 84,</i> 327-471, 1998.</li>
<li>Love and Brownlee, A direct measurement of the terrestrial
mass accretion rate of cosmic dust, <i>Science, 262,</i> 550-
553, 1993.</li>
<li>Hunten et al., Smoke and dust particles of meteoric origin
in the mesosphere and thermosphere, <i>J. Atm. Sci., 37,</i>
1342-1357, 1980.</li>
<li>McNeil et al.,
Differential ablation of cosmic dust and implications for the
relative abundances of atmospheric metals, <i>J. Geophys.
Res., 103,</i> 10899-10911, 1998.</li>
<li>Thomas, Mesospheric clouds and the physics of the
mesopause region, <i>Rev. Geophys., 29,</i> 553-575,
1991.</li>
<li>Plane, The role of sodium bicarbonate in the nucleation of
noctilucent clouds, <i>Ann. Geophys., 18,</i> 807-814,
2000.</li>
<li>Summers and Siskind, Surface recombination of O and H2 on
meteoric dust as a source of mesospheric water vapor,
<i>Geophys. Res. Lett., 26,</i> 1837-1840, 1999.</li>
</ul>
<h3>about MISU's rocket experiments:</h3>
<ul>
<li>Khaplanov et al., Hygrosonde - A direct measurement of
water vapour in the stratosphere and mesosphere, <i>Geophys.
Res. Lett., 23,</i> 1645, 1996.</li>
<li>Gumbel et al., Scattering phase functions and particle
sizes in noctilucent clouds, <i>Geophys. Res. Lett., 28,</i>
1415-1418, 2001.</li>
<li>Gumbel et al., Odd oxygen measurements during the NLC-93
rocket campaign, <i>J. Geophys. Res., 103,</i> 23399-23414,
1998.</li>
<li>Gumbel, Aerodynamic influences on atmospheric in situ
measurements from sounding rockets, <i>J. Geophys. Res.,
106,</i> 10553-10563, 2001.</li>
<li>Horányi et al., Simulation of rocket-borne particle
measurements in the mesosphere, <i>Geophys. Res. Lett.,
26,</i> 1537-1540, 1999.</li>
</ul>
<h2>More Information</h2>
<p>If you are interested in further information about the
MAGIC project, contact <strong>Jörg Gumbel</strong>
(gumbel@<i></i>misu.su.se). Stay tuned and check
this website for results of the MAGIC campaign in January
2005!</p>
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<p>The <a href="http://www.misu.su.se/ap.html"
target="_top">Atmospheric Physics</a> Group</p>
<p>The <a href="http://www.misu.su.se" target="_top">Department
of Meteorology</a> at <a href="http://www.su.se"
target="_top">Stockholm University</a></p>
<hr />
<address>Last updated: 2004-12-10, Jörg Gumbel
(gumbel@<i></i>misu.su.se).</address>
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</center>
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