Trajectory mapping: A tool for validation of trace gas observations

Morris, Gary A.; Gleason, J. F.; Ziemke, J. R.; Schoeberl, M. R.

doi:10.1029/1999jd901118

Cited by 36 publications

(43 citation statements)

References 38 publications

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“…It is therefore possible to extend sparse ozonesonde measurements and to fill the gaps in the spatial domain by trajectory calculations, assuming the ozone mixing ratio along each trajectory path is constant. This is a technique that has been used successfully with other stratospheric data (Sutton et al, 1994;Newman and Schoeberl, 1995;Morris et al, 2000), and with ozone data in both the stratosphere and troposphere. Stohl et al (2001) used trajectory statistics to extend one year of MOZAIC (Measurement of Ozone and Water Vapour by Airbus In-service Aircraft) ozone measurements into a 4-season ozone climatology at a 10 • × 6 • (longitude by latitude) horizontal grid and three vertical heights.…”

Section: Introductionmentioning

confidence: 99%

A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

et al. 2013

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Abstract. This study explores a domain-filling trajectory approach to generate a global ozone climatology from relatively sparse ozonesonde data. Global ozone soundings comprising 51 898 profiles at 116 stations over 44 yr are used, from which forward and backward trajectories are calculated from meteorological reanalysis data to map ozone measurements to other locations and so fill in the spatial domain. The resulting global ozone climatology is archived monthly for five decades from the 1960s to the 2000s on a grid of 5 • × 5 • × 1 km (latitude, longitude, and altitude), from the surface to 26 km altitude. It is also archived yearly for the same period. The climatology is validated at 20 selected ozonesonde stations by comparing the actual ozone sounding profile with that derived through trajectory mapping of ozone sounding data from all stations except the one being compared. The two sets of profiles are in good agreement, both overall with correlation coefficient r = 0.991 and root mean square (RMS) of 224 ppbv and individually with r from 0.975 to 0.998 and RMS from 87 to 482 ppbv. The ozone climatology is also compared with two sets of satellite data from the Satellite Aerosol and Gas Experiment (SAGE) and the Optical Spectrography and InfraRed Imager System (OSIRIS). The ozone climatology compares well with SAGE and OSIRIS data in both seasonal and zonal means. The mean differences are generally quite small, with maximum differences of 20 % above 15 km. The agreement is better in the Northern Hemisphere, where there are more ozonesonde stations, than in the Southern Hemisphere; it is also better in the middle and high latitudes than in the tropics where reanalysis winds are less accurate. This ozone climatology captures known features in the stratosphere as well as seasonal and decadal variations of these features. The climatology clearly shows the depletion of ozone from the 1970s to the mid 1990s and ozone increases in the 2000s in the lower stratosphere. When this climatology is used as the upper boundary condition in an Environment Canada operational chemical forecast model, the forecast is improved in the vicinity of the upper troposphere-lower stratosphere (UTLS) region. This ozone climatology is latitudinally, longitudinally, and vertically resolved and it offers more complete high latitude coverage as well as a much longer record than current satellite data. As the climatology depends on neither a priori data nor photochemical modeling, it provides independent information and insight that can supplement satellite data and model simulations of stratospheric ozone.

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Section: Introductionmentioning

confidence: 99%

A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

et al. 2013

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“…We therefore present an alternate approach to Match that does not rely upon such filters. This approach follows from the development of trajectory mapping as employed by Morris et al (1995Morris et al ( , 2000, Danilin et al (2000), and others and was first developed by Pierce et al (1994). In this approach, all advected air parcels that arrive within the specified Match radius and within an appropriate vertical distance of the new observation are considered matches with the new ozone measurement.…”

Section: Methodsmentioning

confidence: 99%

“…Such a result suggests that the increased error that results from including longer, and hence more uncertain trajectories, is more than offset by the increased number of matches that result from considering more and longer trajectories. Although 14-day trajectory calculations appear at the upper end of the range of trajectory durations recommended in previous trajectory studies (e.g., Morris et al, 1995;Morris et al, 2000) we nevertheless recommend extending trajectory calculations to 14 days for future Match analysis.…”

Section: Trajectory Durationmentioning

confidence: 99%

A review of the Match technique as applied to AASE-2/EASOE and SOLVE/THESEO 2000

et al. 2005

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Abstract. We apply the NASA Goddard Trajectory Model to data from a series of ozonesondes to derive ozone loss rates in the lower stratosphere for the AASE-2/EASOE mission (January-March 1992) and for the SOLVE/THESEO 2000 mission (January-March 2000) in an approach similar to Match. Ozone loss rates are computed by comparing the ozone concentrations provided by ozonesondes launched at the beginning and end of the trajectories connecting the launches. We investigate the sensitivity of the Match results to the various parameters used to reject potential matches in the original Match technique. While these filters effectively eliminate from consideration 80% of the matched sonde pairs and >99% of matched observations in our study, we conclude that only a filter based on potential vorticity changes along the calculated back trajectories seems warranted. Our study also demonstrates that the ozone loss rates estimated in Match can vary by up to a factor of two depending upon the precise trajectory paths calculated for each trajectory. As a result, the statistical uncertainties published with previous Match results might need to be augmented by an additional systematic error. The sensitivity to the trajectory path is particularly pronounced in the month of January, for which the largest ozone loss rate discrepancies between photochemical models and Match are found. For most of the two study periods, our ozone loss rates agree with those previously published. Notable exceptions are found for January 1992 at 475 K and late February/early March 2000 at 450 K, both periods during which we generally find smaller loss rates than the previous Match studies. Integrated ozone loss rates estimated by Match in both of those years compare well with those found in numerous other studies and in a potential vorticity/potential temperature approach shown previously and in this paper. Finally, we suggest an alternate approach to Match using trajectory mapping. This approach uses inforCorrespondence to: G. A. Morris (gary.morris@valpo.edu) mation from all matched observations without filtering and uses a two-parameter fit to the data to produce robust ozone loss rate estimates. As compared to loss rates from our version of Match, the trajectory mapping approach produces generally smaller loss rates, frequently not statistically significantly different from zero, calling into question the efficacy of the Match approach.

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“…It is therefore possible to employ a technique that has been used successfully in the stratosphere (Sutton et al, 1994;Newman and Schoeberl, 1995;Morris et al, 2000) and use forward and backward trajectory calculations for each sounding to map ozone measurements to a number of other locations, and so to fill in the spatial domain. In the troposphere, trajectories have larger errors than in the stratosphere (Stohl and Seibert, 1998), primarily because of the importance of vertical motion, which is difficult to model accurately, but also because of turbulence in the boundary layer.…”

Section: G Liu Et Al: a Global Tropospheric Ozone Climatology From mentioning

confidence: 99%

A global tropospheric ozone climatology from trajectory-mapped ozone soundings

Liu

Tarasick

et al. 2013

Atmos. Chem. Phys.

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Abstract.A global three-dimensional (i.e. latitude, longitude, altitude) climatology of tropospheric ozone is derived from the ozone sounding record by trajectory mapping. Approximately 52 000 ozonesonde profiles from more than 100 stations worldwide since 1965 are used. The small number of stations results in a sparse geographical distribution. Here, forward and backward trajectory calculations are performed for each sounding to map ozone measurements to a number of other locations, and so to fill in the spatial domain. This is possible because the lifetime of ozone in the troposphere is of the order of weeks. This physically based interpolation method offers obvious advantages over typical statistical interpolation methods. The trajectory-mapped ozone values show reasonable agreement, where they overlap, to the actual soundings, and the patterns produced separately by forward and backward trajectory calculations are similar. Major regional features of the tropospheric ozone distribution are clearly evident in the global maps. An interpolation algorithm based on spherical functions is further used for smoothing and to fill in remaining data gaps. The resulting three-dimensional global tropospheric ozone climatology facilitates visualization and comparison of different years, decades, and seasons, and offers some intriguing insights into the global variation of tropospheric ozone. It will be useful for climate and air quality model initialization and validation, and as an a priori climatology for satellite data retrievals. Further division of the climatology into decadal and annual averages can provide a global view of tropospheric ozone changes, although uncertainties with regard to the performance of older sonde types, as well as more recent variations in operating procedures, need to be taken into account.

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Trajectory mapping: A tool for validation of trace gas observations

Cited by 36 publications

References 38 publications

A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

A review of the Match technique as applied to AASE-2/EASOE and SOLVE/THESEO 2000

A global tropospheric ozone climatology from trajectory-mapped ozone soundings

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