Blar i NTNU Open på forfatter "Espy, Patrick Joseph"
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A comparison of Gravity Wave Parameters derived from the Analysis of a Three-Field Photometer with Imagers
Bakken, Irene (Master thesis, 2015)A method for preprocessing and analysing a few select fields in airglow intensity images from an all-sky imager was developed and utilized. Waves detected with a three-field analysis were compared with those waves ... -
A new algorithm for remote sensing mesopause temperatures using the hydroxyl airlgow
Hennum, Endre Asheim (Master thesis, 2013)Ground based measurements of the hydroxyl airglow started in Trondheim (63.4 N, 10.4 E) 20. November 2012 using a linear InGaAs PDA detector covering the ∼1450-1650 nm wavelength range. The instrument have suc- cessfully ... -
Aeronomy of hydroxyl airglow variability by means of high-resolution telescope observations and gravity wave simulations
Franzen, Christoph (Doctoral theses at NTNU;2019:202, Doctoral thesis, 2019)Are there waves on the fjord right now? “Easy to find out”, you might think. Just go down to the water and have a look. Now imagine that you are in Oppdal, about 90 kilometres away, trying to see the waves on the fjord in ... -
Airglow Derived Measurements of Q-Branch Transition Probabilities for Several Hydroxyl Meinel Bands
Franzen, Christoph; Espy, Patrick Joseph; hofmann, niklas; Hibbins, Robert; Djupvik, Anlaug Amanda (Journal article; Peer reviewed, 2019)Spectroscopic measurements of the hydroxyl (OH) airglow emissions are often used to infer neutral temperatures near the mesopause. Correct Einstein coefficients for the various transitions in the OH airglow are needed to ... -
Atmospheric Correction over Coastal Waters Based on Machine Learning Models
Borge, Ole Martin (Master thesis, 2020)Atmospheric correction (AC) is often the first step in ocean-color remote sensing algorithms for satellites and would ideally remove atmospheric and ocean surface radiances to produce water-specific properties like the ... -
Atmospheric ozone above Troll station, Antarctica observed by a ground based microwave radiometer
Daae, Marianne; Straub, Corinne; Espy, Patrick Joseph; Newnham, David (Journal article; Peer reviewed, 2014)This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT), ... -
Atmospheric tomography using the Nordic Meteor Radar Cluster and Chilean Observation Network de Meteor Radars: Network details and 3D-Var retrieval
Stober, Gunter; Kozlovsky, A.; Liu, Alan; Qiao, Zishun; Tsutsumi, Masaki; Hall, Chris; Nozawa, Satonori; Lester, Mark; Belova, Evgenia; Kero, Johan; Espy, Patrick Joseph; Hibbins, Robert E.; Mitchell, N. (Peer reviewed; Journal article, 2021)Ground-based remote sensing of atmospheric parameters is often limited to single station observations by vertical profiles at a certain geographic location. This is a limiting factor for investigating gravity wave dynamics ... -
Behaviour of the S1 and S2 Components of the Semidiurnal Tide in the MLT
Backer-Owe, Kåre (Master thesis, 2016)9 years (2000-2008) of wind data from a longitudinal chain of up to 10 Super Dual Auroral Radar Network (SuperDARN) radars spanning over 184 degrees in longitude and ranging in latitude from 51.4 - 65.7 degrees N is used ... -
Benchmarking microbarom radiation and propagation model against infrasound recordings: a vespagram-based approach
Vorobeva, Ekaterina; De Carlo, Marine; Le Pichon, Alexis; Espy, Patrick Joseph; Näsholm, Sven Peter (Journal article; Peer reviewed, 2021)This study investigates the use of a vespagram-based approach as a tool for multi-directional comparison between simulated microbarom soundscapes and infrasound data recorded at ground-based array stations. Data recorded ... -
Characterisation of quasi-stationary planetary waves in the Northern MLT during summer
Stray, Nora Henriette; Espy, Patrick Joseph; Limpasuvan, Varavut; Hibbins, Robert (Journal article; Peer reviewed, 2015)Observations of planetary wave (PW) activity in the northern hemisphere, polar summer mesosphere and lower thermosphere (MLT) are presented. Meteor winds from a northern hemisphere chain of SuperDARN radars have been used ... -
Characteristics and sources of gravity waves observed in noctilucent cloud over Norway
Demissie, Teferi Dejene; Espy, Patrick Joseph; Stray, Nora Henriette; Hatlen, Morten; Kaifler, Natalie; Baumgarten, G (Journal article; Peer reviewed, 2014)Four years of noctilucent cloud (NLC) images from an automated digital camera in Trondheim and results from a ray-tracing model are used to extend the climatology of gravity waves to higher latitudes and to identify ... -
Climatological Westward‐Propagating Semidiurnal Tides and Their Composite Response to Sudden Stratospheric Warmings in SuperDARN and SD‐WACCM‐X
Zhang, Z.; Limpasuvan, Varavut; Orsolini, Yvan J.; Espy, Patrick Joseph; Hibbins, Robert (Peer reviewed; Journal article, 2021)Using the Super Dual Auroral Radar Network observations (clustered around 60°N) and NCAR CESM2.0 extended Whole Atmosphere Community Climate Model nudged with reanalyzes, we examine the climatology of semidiurnal tides in ... -
Climatology of gravity wave activity in Antarctica
Kringlebotn, Ole Martin Granhus (Master thesis, 2020)Målinger har blitt gjort av natthimmellys fra OH ved å bruke et Michelson interferometer. Målingene ble gjennomført ved Rothera (68°S, 68°W) over en periode på åtte år fra 2002 til slutten av 2009. I denne oppgaven studeres ... -
Comparison of mesospheric winds from a high-altitude meteorological analysis system and meteor radar observations during the boreal winters of 2009-2010 and 2012-2013
McCormack, J; Hoppel, K; Kuhl, D; de Wit, R; Stober, G.; Espy, Patrick Joseph; Baker, N; Brown, P; Fritts, D; Jacobi, C.; Janches, D; Mitchell, N.; Ruston, B; Swadley, S; Viner, K; Whitcomb, T; Hibbins, Robert (Journal article; Peer reviewed, 2017)We present a study of horizontal winds in the mesosphere and lower thermosphere (MLT) during the boreal winters of 2009–2010 and 2012–2013 produced with a new high-altitude numerical weather prediction (NWP) system. This ... -
Coupling in the middle atmosphere related to the 2013 major sudden stratospheric warming
De Wit, Rosmarie Johanna; Hibbins, Robert; Espy, Patrick Joseph; Hennum, Endre Asheim (Journal article; Peer reviewed, 2015)The previously reported observation of anomalous eastward gravity wave forcing at mesopause heights around the onset of the January 2013 major sudden stratospheric warming (SSW) over Trondheim, Norway (63° N, 10° E), is ... -
Developing an analysis technique for identification of wave structures in MATS data
Fjeldstad, Andreas (Master thesis, 2018)This thesis presents a method for analyzing data gathered during the MATS mission. The MATS mission is a Swedish satellite mission which aims to improve our understanding of gravity waves in the mesosphere and their influence ... -
Development of a spectrometer system to remotely sense mesospheric temperature.
Berge, Frank Terje (Master thesis, 2011)At nighttime the strongest source of radiation is the hydroxyl night glow. By measuringthe different lines within a band it is possible to calculate the temperature of the mesosphere more than 85km above ground. In order ... -
Electrojet Estimates From Mesospheric Magnetic Field Measurements
Laundal, Karl Magnus; Yee, J.H.; Merkin, V.G.; Gjerløv, Jesper; Vanhamäki, H.; Reistad, Jone Peter; Madelaire, Michael; Sorathia, K.; Espy, Patrick Joseph (Peer reviewed; Journal article, 2021)The auroral electrojet is traditionally measured remotely with magnetometers on ground or in low Earth orbit (LEO). The sparse distribution of measurements, combined with a vertical distance of some 100 km to ground and ... -
Electromagnetic Principles for In Situ Ice Thickness Determination - Field Experiments and Development of New Methods for Interpretation
Lorentzen, Johannes P (Master thesis, 2015)During the spring of 2014 fieldwork in three different locations on Svalbard was conducted in order to investigate the application of electromagnetic methods on sea ice and ice ridges. Two validation grids, one transect ... -
Gravity Wave Refraction in the Atmosphere:: Ray tracing versus Geometric Location from a Single Image
Nærø, Karoline (Master thesis, 2013)This thesis presents two methods of finding the sources of gravity waves observed in the night-time hydroxyl airglow; ray-tracing and geometric localisation by fitting concentric circles onto the curvature of the gravity ...