Hansford Ucam Ozone

67 %
33 %
Information about Hansford Ucam Ozone
Education

Published on February 20, 2008

Author: Ubert

Source: authorstream.com

In Situ Measurements of Ozone during Hibiscus 2004:  In Situ Measurements of Ozone during Hibiscus 2004 Contributions through provision of data and discussions: Niels Larsen (DMI ozonesondes) Gerhard Held, José Mauricio Leite, Bruno Biazon, Pierre Dedieu (preparation and processing of IPMet RS80 & O3 sondes) Georges Durry, Nadir Amarouche (mSDLA) Tom Gardiner, Nigel Swann (TDLAS) Alain Hauchcorne (MIMOSA) G. M. Hansford, R. A. Freshwater, R. L. Jones Outline:  Outline Assessment of 13 Ozonesondes (DMI/IPMet) launched during Hibiscus TTL characteristics: temperature, lapse rate, saturated water vapour mixing ratio profiles and their relation to ozone Definition of the TTL appropriate to Bauru Individual flights: anomalies, relation to PV Assessment of UCAM solid-state ozone sensor measurements on SF flights Correlations with other tracers: CH4, H2O, CO2 Comparison with Theseo 2000 correlations All Ozonesondes launched during Hibiscus:  All Ozonesondes launched during Hibiscus Flat mixing ratio in the troposphere 11th Feb and 6th Mar are anomalous in the altitude range 12 – 16 km Slide4:  MIMOSA PV Maps at 350K: Selected Dates 350K corresponds to ~13.6 km, 165 hPa 11th Feb and 6th Mar show high PV at this level other dates show normal PV characteristic of the tropics Slide5:  Ozonesondes: Averages and Ambient Temperature Ozonopause in the average profile occurs at 13.66 km Except for the boundary layer, the TTL shows greatest variability Standard deviation is only ~5% above 20 km Broad temperature minimum in individual and average profiles Cold-point tropopause at 17.56 km (-75.9ºC) in the average profile Variability also greatest in the TTL, though less pronounced than ozone Slide6:  Ozonesondes: Lapse Rate and Saturated Water Vapour MR Clear TTL signature 13.4 – 17.8 km Local minimum in the average lapse rate at 13.42 km Lapse rate profiles very noisy Very flat SWVMR between 15.0 – 17.8 km Minimum in the average profile is 12.2 ppmv Individual minima are more important? Dataset minimum is 6.0 ppmv on the 20th Feb Slide7:  TTL Statistics from Ozonesonde Series Definitions of the TTL Highwood and Hoskins (1998): extending from the main convective outflow to the cold point. Sherwood and Dessler (2001): the region where convection overshoots its level of neutral buoyancy. Vömel et al. (2002): TTL lower boundary can be defined by a local minimum in relative humidity. Thuburn and Craig (2002): region where radiation is more important than convection, but convection is more important than chemical ozone production. Gettelman and Forster (2002): lower boundary marked by the lapse rate minimum, upper boundary by the cold point. Slide8:  Individual Profile: 16th February 2004 TTL extends from 14.2 – 19.2 km (lapse rate minimum to secondary temperature minimum) Cold-point at 16.4 km Although a clear lapse rate minimum is apparent in this dataset, many show multiple local minima in the range 10 – 15 km Conclusion The Gettelman and Forster criteria for the TTL boundaries are not appropriate for this region of the tropics. TTL definition appropriate for Bauru? – Lower boundary: change in gradient in ozone mixing ratio. Upper boundary: decrease in ozone variability.  14.0 – 17.9 km This definition reflects the potentially greater role of horizontal transport/mixing at TTL altitudes relative to sites closer to the equator. Slide9:  SF4 24th Feb 2004: O3 (O3-SSS), CH4, CO2 (mSDLA) Ascent Profiles No clear correlations between any of these tracers Slide10:  SF4 24th Feb 2004: O3 (O3-SSS), H2O (mSDLA) Descent Profiles Anti-correlation between ozone and water vapour 16.5 – 19 km Major features occur at similar altitudes Slide11:  SF2 13th Feb 2004: O3 (O3-SSS), CH4 (mSDLA) Ascent Profiles No significant correlations over any extended altitude range Slide12:  SF2 13th Feb 2004: O3 (O3-SSS), H2O (mSDLA) Descent Profiles No significant correlations over any extended altitude range (large feature at 6 km correlated?) Slide13:  SF3 26th Feb 2004: O3 (O3-SSS), H2O (TDLAS) Anti-correlation during descent between 10.5 and 13.5 km No other significant correlations Slide14:  THESEO-2000: O3 (O3-SSS), CH4 (TDLAS) Much more obvious (anti-)correlations seen between ozone and methane above Kiruna But, these profiles represent mostly stratospheric air Slide15:  Summary of Tracer Correlations on SF Flights These results need to be interpreted in terms of origin of air – are any (anti-)correlations expected? Slide16:  Future Work Ozonesondes Calculate photochemical ozone production rates in the lower TTL, and check for a positive correlation between ozone and lapse rate above ~14 km (Folkins et al, 1999) Check ancillary data for 11th Feb and 6th Mar to understand elevated ozone in the 12 - 16 km range on these dates SF flights Interpretation of (lack of) correlations between ozone and other tracers Comparison with back-trajectories

Add a comment

Related presentations

Related pages

HTT Workshop Bauru 16-19 Nov 2005

Regional Modelling of Lightning NOx and Ozone: ... L. Jones - UCAM. Zonal distribution of ozone, ... during Hibiscus 2004 - Graeme Hansford, ...
Read more

Dear Colleagues, - DLR Portal

Regional Modelling of Lightning NOx and Ozone: ... T.W. Choularton & H. Coe, UMIST; G. Held, IPMet; A. Robinson, UCAM and J. Gomes, CPTEC ...
Read more

Cloud Resolving Model studies of tropical deep convection ...

Hansford (3). (1) The University of ... UCAM, Cambridge, United Kingdom. The UK Met Office Large Eddy Model (LEM) Cloud Resolving Model ... ozone and ...
Read more

ACP - Abstract - An overview of the HIBISCUS campaign

... R. L. Jones 5, A. D. Robinson 5, G. Hansford 5, L. Eden 5, T ... (UCAM), Dept. of Chemistry ... ozone and ice particles show strong episodic local ...
Read more

HIBISCUS / TroCCiBras / TROCCINOX Workshop

HIBISCUS /TroCCiBras/TROCCINOX Workshop ... Link with definition of TTL G. Hansford / JPP High tropospheric ozone episodes ... Hansford Graeme UCAM, ...
Read more

References

... P. 5 Jones R. L. 5 Robinson A. D. 5 Hansford G. 5 Eden L. 5 Gardiner T. 6 Swann N. 6 Knudsen ... (UCAM), Dept. of ... ozone and ice particles show ...
Read more

Full-text - Isentropic advection and convective lifting of ...

Official Full-Text Publication ... a solid-state semiconductor sensor developed at UCAM Cam-bridge (Hansford ... The observed dependence of ozone on ...
Read more

Isentropic advection and convective lifting of water vapor ...

Isentropic advection and convective lifting of ... a solid-state semiconductor sensor developed at UCAM Cam-bridge (Hansford ... The ozone measurements ...
Read more