Winter temperature tides from 30 to 110 km at McMurdo (77.8

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TitleWinter temperature tides from 30 to 110 km at McMurdo (77.8°S, 166.7°E), Antarctica: Lidar observations and comparisons with WAMAbstractWe provide the first characterization of diurnal and semidiurnal thermal tides in temperature from 30 to 110 km in the winter season (May through August) at McMurdo (77.8 deg S, 166.7 deg E), Antarctica. The observations were made with an Fe Boltzmann temperature lidar in 2011 and 2012. Over 330 h of winter data are compiled into a composite day of temperature perturbations that significantly reduce the incoherent wave effects while preserving the coherent tidal signatures. Both diurnal and semidiurnal tides have small amplitudes (less than 3 K) below 100 km with vertical wavelengths of ~ 29 and ~ 23 km, respectively. A new finding of this study is the fast growth of diurnal and semidiurnal tidal amplitudes above 100 km to at least 15 K near 110 km, exceeding that of the freely propagating tides originating from the lower atmosphere. Such fast growth exists for all Kp index cases and diurnal amplitude increases to 15-30 K at 110 km with larger Kp indices corresponding to larger tidal amplitudes and faster growth rates. The slopes of diurnal tidal phases become steeper above 100 km, and the tidal phases barely change with altitude from 100 to 106 km. The tidal growth behavior is reproduced in the Whole Atmosphere Model (WAM) with phases comparable to the observations but magnitudes significantly underestimated. WAM compares reasonably well with the observations below 100 km. The observed significant amplitude increases and phase structure changes suggest additional tidal sources near or above 100 km, which deserve future investigation. Key Points Temperature tides from 30 to 110 km are characterized with lidar and WAM at McMurdo A new finding is the fast growth of 24 and 12 h tidal amplitudes above 100 km Larger Kp indices correspond to larger tidal amplitudes and faster growth rates Copyright2014. American Geophysical Union. All Rights Reserved.AcknowledgementsWe sincerely acknowledge Wentao Huang, John A. Smith, and Zhangjun Wang for their contributions to the McMurdo Lidar campaign. We are in debted to Jeffery M. Forbes for hisinvaluable advice. We are grateful to Wenbin Wang and Elsayed Talaat for their inspirational suggestions. We also appreciate Fei Wu and Rashid A. Akmaev for running and preparing WAM data. We thank the staff of the United States Antarctic Program, McMurdo Station, Antarctica New Zealand, and Scott Base for their support. We offer special thanks to Vladimir Papitashvili for his encouragement and help in this research. The lidar project was supported by NSF grants ANT-0839091 and PLR-1246405. X.L. sincerely acknowledges the generous support of the CIRES Visiting Fellows Program (http://cires.colorado.edu/collaboration/fellowships/). MERRA data used in this study were provided by the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space FlightCenter through the NASA GES DISConline archive.Funding DetailsANT-0839091, NSF, National Science Foundation; PLR-1246405, NSF, National Science Foundation

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1st AuthorFong, W.AuthorFong, W.Lu, X.Chu, X.Fuller-Rowell, T.Yu, Z.Roberts, B.Chen, C.Gardner, C.McDonald, A.Year2014JournalJournal of Geophysical Research AtmospheresVolume119Number6Pages2846-2863DOI10.1002/2013JD020784URLhttps://www.scopus.com/inward/recor.....32be49944c5cc702073066d8eKeywordsGeomagnetismOptical radarTides, AntarcticaAtmosphere modelingGeomagnetic activitiesLower thermosphereTemperature tides, Atmospheric temperature, amplitudeatmospheric modelinggeomagnetic fieldlidarmagnitudeobservational methodtemperature effectthermospherewavelengthwinter, AntarcticaEast AntarcticaMcMurdo Sound, rank5Author Keywordsgeomagnetic activitylidarlower thermospheretemperature tidesWhole Atmosphere Modelwinter Antarctica

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TypeArticleCitationFong, W., Lu, X., Chu, X., Fuller-Rowell, T., Yu, Z., Roberts, B., Chen, C., Gardner, C. and McDonald, A. (2014). Winter temperature tides from 30 to 110 km at {McMurdo} {(77.8$\,^{\circ}$S, 166.7$\,^{\circ}$E)}, {Antarctica}: Lidar observations and comparisons with {WAM}. Journal of Geophysical Research Atmospheres, 119(6): 2846-2863 IdentifierFong2014Relevancerank5