Climatology of middle atmospheric water vapour above the ALOMAR observatory in northern Norway

Abstract. We have been observing the water vapour line at 22.235 GHz above ALOMAR in northern Norway (69° N, 16° E) since early 1996 with ground-based microwave spectrometers (WASPAM and cWASPAM) and will here describe a climatology based on these observations. Maintenance, different spectrometers and upgrades of the hardware have slightly changed the instruments. Therefore great care has been taken to make sure the different datasets are compatible with each other. In order to maximise the sensitivity at high altitude for the older instrument a long integration time (168 h) was chosen. The complete dataset was thereafter recompiled into a climatology which describes the yearly variation of water vapour at polar latitudes on a weekly basis. The atmosphere is divided into 16 layers between 40–80 km, each 2.5 km thick. The dataset, spanning 15 yr from 1996 to 2010, enabled us to investigate the long-term behaviour of water vapour at these latitudes. By comparing the measurements from every year to the climatological mean we were also able to look for indications of trends in the dataset at different altitudes during the time period of our observations. In general there is a weak negative trend which differs slightly at different altitudes. There are however no drifts in the annual variation of water vapour from the point of view of onset of summer and winter. We compare our climatology to the reference water vapour profiles from AFGL, a free and easy accessible reference atmosphere. There are strong deviations between our observations and the reference profile, therefore we publish our climatological dataset in a table in the paper.

[1]  D. Murtagh,et al.  Bright polar mesospheric clouds formed by main engine exhaust from the space shuttle's final launch , 2012 .

[2]  P. Hartogh,et al.  Anthropogenic effects on the distribution of minor chemical constituents in the mesosphere/lower thermosphere – A model study , 2012 .

[3]  K. Hocke,et al.  Transport of mesospheric H 2 O during and after the stratospheric sudden warming of January 2010: observation and simulation , 2011 .

[4]  P. Hartogh,et al.  First detection of tidal behaviour in polar mesospheric water vapour by ground based microwave spectroscopy , 2011 .

[5]  P. Bernath,et al.  Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) data set , 2011 .

[6]  N. Kämpfer,et al.  ARIS-Campaign: intercomparison of three ground based 22 GHz radiometers for middle atmospheric water vapor at the Zugspitze in winter 2009 , 2011 .

[7]  P. Hartogh,et al.  Ozone trends in the mid-latitude stratopause region based on microwave measurements at Lindau (51.66° N, 10.13° E), the ozone reference model, and model calculations , 2011 .

[8]  E. Ray,et al.  Stratospheric water vapor trends over Boulder, Colorado: Analysis of the 30 year Boulder record , 2011 .

[9]  P. Hartogh,et al.  A New, High-performance, Heterodyne Spectrometer for Ground-based Remote Sensing of Mesospheric Water Vapour , 2010 .

[10]  P. Hartogh,et al.  Water vapor measurements at ALOMAR over a solar cycle compared with model calculations by LIMA , 2010 .

[11]  Alyn Lambert,et al.  Validation of ground‐based microwave radiometers at 22 GHz for stratospheric and mesospheric water vapor , 2009 .

[12]  C. Boone,et al.  Water vapor measurements in the mesosphere from Mauna Loa over solar cycle 23 , 2009 .

[13]  J. Laštovička Global pattern of trends in the upper atmosphere and ionosphere: Recent progress , 2009 .

[14]  T. Flury,et al.  Ozone depletion, water vapor increase, and PSC generation at midlatitudes by the 2008 major stratospheric warming , 2009 .

[15]  G. Brasseur,et al.  Aeronomy of the Middle Atmosphere , 2009 .

[16]  P. M. Lang,et al.  Observational constraints on recent increases in the atmospheric CH4 burden , 2009 .

[17]  P. Bernath,et al.  Satellite observations and modeling of transport in the upper troposphere through the lower mesosphere during the 2006 major stratospheric sudden warming , 2009 .

[18]  P. Hartogh,et al.  Analysis of nonlinear effects in microwave spectrometers , 2009 .

[19]  P. Hartogh,et al.  Upper stratospheric ozone decrease events due to a positive feedback between ozone and the ozone dissociation rate , 2009 .

[20]  Shamil Maksyutov,et al.  Decreasing anthropogenic methane emissions in Europe and Siberia inferred from continuous carbon dioxide and methane observations at Alert, Canada , 2009 .

[21]  P. Hartogh,et al.  Ozone distribution in the middle latitude mesosphere as derived from microwave measurements at Lindau (51.66 N, 10.13 E) , 2009 .

[22]  P. Hartogh,et al.  A QBO-signal in mesospheric water vapor measurements at ALOMAR (69.29° N, 16.03° E) and in model calculations by LIMA over a solar cycle , 2009 .

[23]  Derek M. Cunnold,et al.  Renewed growth of atmospheric methane , 2008 .

[24]  S. Bekki,et al.  Diurnal changes in middle atmospheric H2O and O3: Observations in the Alpine region and climate models , 2008 .

[25]  U. Berger Modeling of middle atmosphere dynamics with LIMA , 2008 .

[26]  K. Rosenlof,et al.  Trends in the temperature and water vapor content of the tropical lower stratosphere: Sea surface connection , 2008 .

[27]  P. Hartogh,et al.  The quasi 5-day signal in the mesospheric water vapor concentration at high latitudes in 2003 - A comparison between observations at ALOMAR and calculations , 2008 .

[28]  P. Hartogh,et al.  Long-term trends of the concentration of the minor constituents in the mesosphere - a model study , 2007 .

[29]  J. Staehelin,et al.  Trends and variability of midlatitude stratospheric water vapour deduced from the re-evaluated Boulder balloon series and HALOE , 2007 .

[30]  E. Dupuy,et al.  Global observations of middle atmospheric water vapour by the Odin satellite: An overview. , 2007 .

[31]  Rolando R. Garcia,et al.  Simulation of secular trends in the middle atmosphere, 1950–2003 , 2007 .

[32]  Holger Vömel,et al.  Decreases in stratospheric water vapor after 2001: Links to changes in the tropical tropopause and the Brewer‐Dobson circulation , 2006 .

[33]  P. Hartogh,et al.  A digital dispersive matching network for SAW devices in chirp transform spectrometers , 2006, IEEE Transactions on Microwave Theory and Techniques.

[34]  U. Berger,et al.  Autocatalytic water vapor production as a source of large mixing ratios within the middle to upper mesosphere , 2005 .

[35]  David E. Siskind,et al.  Observations of stratospheric warmings and mesospheric coolings by the TIMED SABER instrument , 2005 .

[36]  Paul Hartogh,et al.  Noctilucent clouds and the mesospheric water vapour : the past decade , 2004 .

[37]  Paul Hartogh,et al.  The High Resolution Chirp Transform Spectrometer for the Sofia-Great Instrument , 2004 .

[38]  Paul Hartogh,et al.  On the spatiotemporal behavior of ozone within the upper mesosphere/mesopause region under nearly polar night conditions , 2004 .

[39]  P. M. Lang,et al.  Atmospheric methane levels off: Temporary pause or a new steady‐state? , 2003 .

[40]  M. Rapp,et al.  Polar mesospheric clouds formed from space shuttle exhaust , 2003 .

[41]  T. Shepherd The middle atmosphere , 2000 .

[42]  Paul Hartogh,et al.  A case study on middle atmospheric water vapor transport during the February 1998 stratospheric warming , 2000 .

[43]  P. Hartogh,et al.  Water vapor of the polar middle atmosphere: Annual variation and summer mesosphere Conditions as observed by ground‐based microwave spectroscopy , 1999 .

[44]  Franz-Josef Lübken,et al.  Thermal structure of the Arctic summer mesosphere , 1999 .

[45]  U. Langematz,et al.  A note on record‐high temperatures at the northern polar stratopause in winter 1997/98 , 1998 .

[46]  Paul Hartogh,et al.  Present and future chirp transform spectrometers for microwave remote sensing , 1997, Remote Sensing.

[47]  R. R. Conway,et al.  Implications of Satellite OH Observations for Middle Atmospheric H2O and Ozone , 1997 .

[48]  R. Bevilacqua,et al.  Measurements of water vapor in the middle atmosphere and implications for mesospheric transport , 1996 .

[49]  P. Mote,et al.  An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor , 1996 .

[50]  Paul Hartogh,et al.  Ground-based detection of middle atmospheric water vapor , 1995, Remote Sensing.

[51]  Paul Hartogh,et al.  Retrieval of data from ground-based microwave sensing of the middle atmosphere: comparison of two inversion techniques , 1995, Remote Sensing.

[52]  J. Holton,et al.  Stratosphere‐troposphere exchange , 1995 .

[53]  Carl A. Reber,et al.  The Upper Atmosphere Research Satellite (UARS) mission , 1993 .

[54]  P. Hartogh,et al.  Simultaneous Water Vapour And Ozone Measurements with Millimeterwaves In The Stratosphere And Mesosphere , 1991, [Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management.

[55]  P. Hartogh,et al.  A high-resolution chirp transform spectrometer for microwave measurements , 1990 .

[56]  F. X. Kneizys,et al.  AFGL atmospheric constituent profiles (0-120km) , 1986 .

[57]  F. X. Kneizys,et al.  AFGL (Air Force Geophysical Laboratory) atmospheric constituent profiles (0. 120km). Environmental research papers , 1986 .

[58]  Guy Brasseur,et al.  Aeronomy of the Middle Atmosphere: Chemistry and Physics of the Stratosphere and Mesosphere , 1984 .

[59]  R. McPherson,et al.  The NMC Operational Global Data Assimilation System , 1979 .

[60]  R. Minzner The 1976 Standard Atmosphere and its relationship to earlier standards , 1977 .

[61]  C. Rodgers,et al.  Retrieval of atmospheric temperature and composition from remote measurements of thermal radiation , 1976 .

[62]  K. Labitzke Temperature Changes in the Mesosphere and Stratosphere Connected with Circulation Changes in Winter , 1972 .

[63]  W. V. Snyder,et al.  Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements , 2007 .

[64]  Paul Hartogh,et al.  Analysis of forward models using the singular value decomposition algorithm , 1997, Remote Sensing.

[65]  M. McCormick,et al.  Proposed reference model for middle atmosphere water vapor , 1996 .

[66]  J. Barnett,et al.  Zonal mean temperature, pressure, zonal wind and geopotential height as functions of latitude , 1990 .

[67]  C. Rodgers,et al.  Performance and early results from the stratospheric and mesospheric sounder (SAMS) on Nimbus 7 , 1981 .