Lehmann, Ralph

Müller, Katrin

Rex, Markus

von der Gathen, Peter

Wohltmann, Ingo

English

Electronic Publication Information Center

References Fueglistaler, S., Wernli, H., and Peter, T.:Tropical troposphere-to-stratosphere transport inferred from trajectory calculations, J.  Geophys. Res., 109, D03108, doi:10.1029/2003JD004069, 2004. Kley, D., Crutzen, P. J., Smit, H. G. J., Vömel, H., Oltmans, S. J., Grassl, H., and Ramanathan, V.: Observations of near-zero ozone concentrations over the convectice Pacific: Effects on air chemistry, Science, 274, 230-233, 1996. Kremser, S., Wohltmann, I., Rex, M., Langematz, U., Dameris, M.,  and Kunze, M.: Water vapour transport in the tropical tropopause region in coupled Chemistry-Climate Models and ERA-40 reanalysis data,  Atmos. Chem. Phys., 9, 2679-2694, 2009. Pan, L.L., Honomichl, S.B., Randel, W.J., Apel, E.C., Atlas, E.L., Beaton, S.P., Bresch, J.F., Hornbrook, R., Kinnison, D.E., Lamarque, J.-F., Saiz-Lopez, A., Salawitch, R.J., and Weinheimer, A.J.: Bimodal distribution of free tropospheric ozone over the tropical western Pacific revealed by airborne observations, Geophys. Res. Lett., 42, 7844-7851, doi:10.1002/2015GL065562, 2015. Rex, M., Wohltmann, I., Ridder, T., Lehmann, R., Rosenlof, K., Wennberg, P., Weisenstein, D., Notholt, J., Krüger, K., Mohr, V., Tegtmeier, S.: A tropical West Pacific OH minimum and implications for stratospheric composition,  Atmos. Chem. Phys., 14, 4827-4841, 2014. Vömel, H. and Diaz, K.: Ozone cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere, Atmos. Meas. Tech., 3, 495, doi:10.5194/amt-3-495-2010, 2010.  Figure „Globe“: Wikipedia. BREMERHAVEN  Am Handelshafen 12 27570 Bremerhaven Telefon 0471 4831-0 www.awi.de Stratospheric and upper tropospheric  processes for better climate predictions StratoClim is funded by the European Union Measuring the Tropospheric Ozone Minimum in the Tropical West Pacific Quadrennial Ozone Symposium, Edinburgh, 04.-09. September 2016 Katrin Müller, Peter von der Gathen, Ingo Wohltmann, Ralph Lehmann und Markus Rex The Tropical West Pacific Major source region for stratospheric air in boreal winter (e.g. Fueglistaler et al. 2004, Kremser et al. 2009) Origin and transit region of corresponding air masses in boundary layer and troposphere (Rex et al. 2014) Persistent tropospheric ozone minimum (Rex et al. 2014) Corresponding OH minimum and prolonged life times of  various chemical species  (e.g. Kley et al. 1996) Lack of (continuous) measurements Important region for the supply of chemical species to the stratosphere  Palau   Oxidizing Capacity • Major source of OH formation in clean tropospheric air:  • Couples ozone concentration and oxidizing capacity • Efficient loss mechanism for ozone, favored in the tropical West Pacific 𝑶𝟑 + 𝒉𝒗 → 𝑶( 𝑫) +𝟏 𝑶𝟐 𝑶( 𝑫) + 𝑯𝟐𝑶 → 𝑶𝑯+𝑶𝑯𝟏  2 4 6 ATLAS relative units Ozone sondes: tropospheric  ozone column b ▲ Fig.1: Density distribution function of the horizontal positions of the trajectories between boundary layer and LCPs from 4-months ATLAS runs; thick red line: TransBrom cruise October 2009 (Rex et al. 2014). ▲ Fig.2: TES monthly mean tropospheric ozone columns for January, April, July, October 2005-2009 (Rex et al. 2014). ◄ Fig.3: Tropospheric columns for (a) ozone and (b) OH from GEOS Chem for October 2009; open circles in (a) TransBrom balloon soundings; pink circle: Palau (Rex et al. 2014). ▼ Fig.4: Tropospheric ozone profiles from TransBrom (black: extratropical ~30°N, red: ~10°N), shading: see fig. 5 (Rex et al. 2014). a Motivated by measurements from the TransBrom campaign in October 2009 with RV Sonne a new research station was established on Palau (7° N, 135° E) as part of the StratoClim EU-project: since January 2016 intensive measurement periods and regular ozone soundings to improve limited data pool.  Development of a new device to monitor the background current of ECC ozone sondes in flight to lower the instrumental detection limit and • improve measurements at mixing ratios near detection limit (~15ppbv) • Improve the overall understanding of this yet controversial bias     (see Vömel und Diaz,2010). Objectives Background Current and Modification of ECC Sondes First Ozone Measurements from Palau ▲►Fig. 7,8,9: Sketch and photos of the ECC sonde modification for in-flight-monitoring of Ib . ▲Abb.6: Sensor current during the complete sounding (left) and comparison of all ‛NoOzone‘ periods (right), grey dashed line: pre-launch background; colours of shading or lines differentiate between different “NoOzone”-periods. ◄Fig. 10. Instrumental setup at the StratoClim Atmospheric Observatory in Palau; next month: ECC-COBALD-CFH soundings during POSIDON (in coop. with NOAA, NASA) and installation of Pandora 2S; continuation of the station after StratoClim with new funding is aspired. Hypothesis: for each trajectory of one specific individual sonde in a 5-dim. parameter space (t, T, p, c[O3], ’shaking’) the background current develops in one specific way. Practical approach: in-flight monitoring of the background current in regions of interest (e.g. tropical upper troposphere) Ozone [ppbv] Altitude [m] Summary: Successful establishment of the new Palauan research station: growing data set from 01/2016 until 2018(+). Under investigation: seasonal variation (incl. El Niño), relation of tropos. O3 and H2O, chemical and dynamical processes in the TTL.  ►Fig. 11. Seasonal variation of tropospheric ozone VMR from preliminary ECC sonde data for 2016. ▼ Fig. 13. Comparison of ozone distributions with respect to relative humidity (RH) (left), magenta: all data, blue: data with RH > 45 %; examples of ozone and RH profiles                   with anti-correlated layers (middle, right).           ◄Fig. 5. Tropospheric ozone profile from the first             modified ECC sonde launch (blue) in Palau. For             comparison: profile from a regular launch 2 hours             prior (magenta). Shading illustrates the effect of different background current (Ib) treatments (see also fig.4). Lowest values: subtraction of a constant Ib; highest values: Ib equals zero; lines: subtraction of a pressure dependent Ib.  ◄ Fig. 12. Relative frequency distribution (normalized by layer maximum) of ozone VMR (0-15km) from all (21 prelim.) profiles. FTIR Spectrometer: Total abundances of ~ 20 chemical species Lidar: Vertical profiles of aerosol properties In 2017: multi-λ cloud and aerosol lidar: ComCAL Research balloons: Vertical profiles of • Ozone (ECC) • Tandem Mod. ECC (Oct‛16) • Aerosol (COBALD) (Oct‛16) • Water vapour (CFH) (Oct‛16) MaxDOAS (Oct. 2016): Pandora2S – Pandonia Network O3, NO2, AOD (, H2O, SO2, …) Hypothesis: for each trajectory of one specific individual sonde in a 5-dim. parameter space (t,T,p,c[O3],’shaking’) the background current develops in one specific way. Background current originates from residual post-preparation contamination in micro-cavities in the cell walls or tubing: thus dependent on the individual sonde.  Practical approach: in-flight monitoring of the background current in regions of interest (e.g. tropical upper troposphere) 

Measuring the Tropospheric Ozone Minimum in the Tropical West Pacific

https://epic.awi.de/id/eprint/52672/1/QOS_poster_A0.pdf

Measuring the Tropospheric Ozone Minimum in the Tropical West Pacific

Abstract

Similar works

Full text

Available Versions

Electronic Publication Information Center