English
norskBlar i forfatter "Havnes, Ove"
Viser treff 1-12 av 12
-
CHARGING AND DETECTION OF MESOSPHERIC DUST WITH INSTRUMENT SPID ON G-CHASER ROCKET
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019)The Smoke Particle Impact Detector (SPID) was flown on the G-Chaser student rocket that was launched from Andøya on 13 January 2019. SPID is a Faraday cup instrument with applied bias voltages to deflect the ambient plasma and a target area inside the probe designed to measure the dust particles by charge detection. The charging process of the dust particles in the detector is important for interpretation ... -
A comparison of overshoot modelling with observations of polar mesospheric summer echoes at radar frequencies of 56 and 224 MHz
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)We have compared radar observations of polar mesospheric summer echoes (PMSEs) modulated by artificial electron heating, at frequencies of 224 MHz (EISCAT VHF) and 56 MHz (MORRO). We have concentrated on 1 day of observation, lasting ~ 3.8 h. The MORRO radar, with its much wider beam, observes one or more PMSE layers all the time while the VHF radar observes PMSEs in 69% of the time. Statistically ... -
Dust charging and density conditions deduced from observations of PMWE modulated by artificial electron heating
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)We present an analysis of relatively strong Polar Mesospheric Winter Echoes (PMWE) under artificial electron heating that changes the PMWE intensity. A major purpose is to find reliable estimates of the relaxation time of the heater modified PMWE to their undisturbed state during the heater switch-off phase; the implications regarding charge/discharge mechanisms; and to exploit the diagnostic potential ... -
Estimates of the size distribution of meteoric smoke particles from rocket-borne impact probes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-26)Ice particles populating noctilucent clouds and being responsible for polar mesosphericsummer echoes exist around the mesopause in the altitude range from 80 to 90 km during polar summer.The particles are observed when temperatures around the mesopause reach a minimum, and it is presumedthat they consist of water ice with inclusions of smaller mesospheric smoke particles (MSPs). This workprovides ... -
Mesospheric dust and its secondary effects as observed by the ESPRIT payload
(Journal article; Tidsskriftartikkel; Peer reviewed, 2009) -
Multi-scale measurements of mesospheric aerosols and electrons during the MAXIDUSTY campaign
(Journal article; Peer reviewed, 2019-04-08)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. <br>Two mechanically identical DUSTY probes mounted with an inter-spacing of ∼10 cm recorded very different currents, with strong spin modulation, ... -
A new method of inferring the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-15)<p>We present a new method of analyzing measurements of mesospheric dust made with DUSTY rocket-borne Faraday cup probes. It can yield the variation in fundamental dust parameters through a mesospheric cloud with an altitude resolution down to 10 cm or less if plasma probes give the plasma density variations with similar height resolution. A DUSTY probe was the first probe that unambiguously detected ... -
Nordlys i verdensrommet
(Journal article; Tidsskriftartikkel, 1980)Vi vil ikke her gå inn i nordlyset som vi kjenner det fra jorden, men kort omtale andre steder i verdensrommet hvor vi har observert nordlyslignende fenomen eller hvor vi kan vente å finne beslektede fenomen. -
Observation of mesospheric dust and ionospheric conditions during the G-chaser rocket campaign
(Conference object; Konferansebidrag, 2019)SPID, Smoke Particle Impact Detector, is a Faraday cup detector designed to measure nanometer-sized meteoric smoke particles during rocket flights. We report measurements made with SPID during the G-Chaser student rocket campaign 13 January 2019 and describe the design of the SPID instruments. Model calculations of dust trajectories within the detector result in an effective cross section of 0.97 ... -
On the Relationship between PMSE Strength and Particle Precipitation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06)We have studied the relationship between particle precipitation and PMSE strength on days where we observe PMSE layers both with the EISCAT VHF and UHF radars. The UHF observations of the ionization and its variation, above the PMSE layer, is used as a measure of precipitation. Variations of the precipitation is compared with variations of the PMSE strengths observed with both radars. Although ... -
On the secondary charging effects and structure of mesospheric dust particles impacting on rocket probes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2007) -
Secondary charging effects due to icy dust particle impacts on rocket payloads
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)We report measurements of dust currents obtained with a small probe and a larger probe during the flight of the ECOMA-4 rocket through the summer polar mesosphere. The payload included two small dust probes behind a larger dust probe located centrally at the front. For certain phases of the payload rotation, the current registered by one of the small dust probes was up to 2 times the current measured ...
