000017014 001__ 17014 000017014 005__ 20240712100838.0 000017014 0247_ $$2DOI$$a10.5194/acp-11-5569-2011 000017014 0247_ $$2WOS$$aWOS:000291939800003 000017014 0247_ $$2Handle$$a2128/9964 000017014 037__ $$aPreJuSER-17014 000017014 041__ $$aeng 000017014 082__ $$a550 000017014 084__ $$2WoS$$aMeteorology & Atmospheric Sciences 000017014 1001_ $$0P:(DE-HGF)0$$aFrey, W.$$b0 000017014 245__ $$aIn-situ measurements of tropical cloud properties in the West African monsoon: upper tropospheric ice clouds, mesoscale convective system outflow, and subvisual cirrus 000017014 260__ $$aKatlenburg-Lindau$$bEGU$$c2011 000017014 300__ $$a5569 - 5590 000017014 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article 000017014 3367_ $$2DataCite$$aOutput Types/Journal article 000017014 3367_ $$00$$2EndNote$$aJournal Article 000017014 3367_ $$2BibTeX$$aARTICLE 000017014 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000017014 3367_ $$2DRIVER$$aarticle 000017014 440_0 $$09601$$aAtmospheric Chemistry and Physics$$v11$$x1680-7316$$y12 000017014 500__ $$3POF3_Assignment on 2016-02-29 000017014 500__ $$aThe SCOUT-O3 and SCOUT-AMMA projects were funded by the European Commission through Contract 505390-GOCE-CT-2004-505390 and the EC Integrated Projects AMMA-EU (Contract no. 004089-2). The M-55 Geophysica campaign was supported by the EEIG-Geophysica Consortium, CNRS-INSU, CNES, and EUFAR. Meteosat Second Generation data were provided by the AMMA database (http://aoc.amma-international.org/observation/satellite/) and were processed including the flight tracks by Sylwester Arabas from the University of Warsaw, Poland.Based on a French initiative, AMMA was built by an international scientific group and funded by a large number of agencies, especially from France, the United Kingdom, the United States, Africa, and - for us - German sources. It has been a beneficiary of a major financial contribution from the European Community Sixth Framework Programme (AMMA-EU). Significant financial support for our activities with the M-55 Geophysica in Australia and Burkina Faso also was supplied by the Max Planck Society.For the CIP data processing we gratefully acknowledge help from Aaron Bansemer (NCAR, Boulder, Co, USA). For very helpful comments on the manuscript we thank Jasmine Cetrone from the University of Washington, Seattle, USA. We thank Stefano Balestri, Ana Alfaro Martinez (ERS), and the pilots, engineers, crew of the M-55 Geophysica. The local authorities, scientists and staff in Ouagadougou (Burkina Faso) were wonderful hosts, and we thank for their amazing hospitality and support during this in many respects challenging campaign in Burkina Faso, which for all of us was a deeply moving life experience. Special thanks are due to Toro Drabo from the University in Ouagadougou. We grateful acknowledge the constructive and helpful comments by Darrel Baumgardner, Grant Allen, and the two anonymous referees. 000017014 520__ $$aIn situ measurements of ice crystal size distributions in tropical upper troposphere/lower stratosphere (UT/LS) clouds were performed during the SCOUT-AMMA campaign over West Africa in August 2006. The cloud properties were measured with a Forward Scattering Spectrometer Probe (FSSP-100) and a Cloud Imaging Probe (CIP) operated aboard the Russian high altitude research aircraft M-55 Geophysica with the mission base in Ouagadougou, Burkina Faso. A total of 117 ice particle size distributions were obtained from the measurements in the vicinity of Mesoscale Convective Systems (MCS). Two to four modal lognormal size distributions were fitted to the average size distributions for different potential temperature bins. The measurements showed proportionately more large ice particles compared to former measurements above maritime regions. With the help of trace gas measurements of NO, NOy, CO2, CO, and O-3 and satellite images, clouds in young and aged MCS outflow were identified. These events were observed at altitudes of 11.0 km to 14.2 km corresponding to potential temperature levels of 346K to 356 K. In a young outflow from a developing MCS ice crystal number concentrations of up to (8.3 +/- 1.6) cm(-3) and rimed ice particles with maximum dimensions exceeding 1.5mm were found. A maximum ice water content of 0.05 gm(-3) was observed and an effective radius of about 90 mu m. In contrast the aged outflow events were more diluted and showed a maximum number concentration of 0.03 cm(-3), an ice water content of 2.3x10(-4) gm(-3), an effective radius of about 18 mu m, while the largest particles had a maximum dimension of 61 mu m.Close to the tropopause subvisual cirrus were encountered four times at altitudes of 15 km to 16.4 km. The mean ice particle number concentration of these encounters was 0.01 cm(-3) with maximum particle sizes of 130 mu m, and the mean ice water content was about 1.4x10(-4) gm(-3). All known in situ measurements of subvisual tropopause cirrus are compared and an exponential fit on the size distributions is established for modelling purposes.A comparison of aerosol to ice crystal number concentrations, in order to obtain an estimate on how many ice particles may result from activation of the present aerosol, yielded low ratios for the subvisual cirrus cases of roughly one cloud particle per 30 000 aerosol particles, while for the MCS outflow cases this resulted in a high ratio of one cloud particle per 300 aerosol particles. 000017014 536__ $$0G:(DE-Juel1)FUEK491$$2G:(DE-HGF)$$aAtmosphäre und Klima$$cP23$$x0 000017014 588__ $$aDataset connected to Web of Science 000017014 65320 $$2Author$$am 000017014 650_7 $$2WoSType$$aJ 000017014 7001_ $$0P:(DE-HGF)0$$aBorrmann, S.$$b1 000017014 7001_ $$0P:(DE-HGF)0$$aKunkel, D.$$b2 000017014 7001_ $$0P:(DE-HGF)0$$aWeigel, R.$$b3 000017014 7001_ $$0P:(DE-HGF)0$$ade Reus, M.$$b4 000017014 7001_ $$0P:(DE-HGF)0$$aSchlager, H.$$b5 000017014 7001_ $$0P:(DE-HGF)0$$aRoiger, A.$$b6 000017014 7001_ $$0P:(DE-HGF)0$$aVoigt, C.$$b7 000017014 7001_ $$0P:(DE-HGF)0$$aHoor, P.$$b8 000017014 7001_ $$0P:(DE-HGF)0$$aCurtius, J.$$b9 000017014 7001_ $$0P:(DE-Juel1)129131$$aKrämer, M.$$b10$$uFZJ 000017014 7001_ $$0P:(DE-Juel1)VDB1410$$aSchiller, C.$$b11$$uFZJ 000017014 7001_ $$0P:(DE-HGF)0$$aVolk, C.M.$$b12 000017014 7001_ $$0P:(DE-HGF)0$$aHoman, M.$$b13 000017014 7001_ $$0P:(DE-HGF)0$$aFierli, F.$$b14 000017014 7001_ $$0P:(DE-HGF)0$$aDi Donfrancesco, G.$$b15 000017014 7001_ $$0P:(DE-HGF)0$$aUlanovsky, A.$$b16 000017014 7001_ $$0P:(DE-HGF)0$$aRavegnani, F.$$b17 000017014 7001_ $$0P:(DE-HGF)0$$aSitnikov, N.M.$$b18 000017014 7001_ $$0P:(DE-HGF)0$$aViciani, S.$$b19 000017014 7001_ $$0P:(DE-HGF)0$$aD'Amato, F.$$b20 000017014 7001_ $$0P:(DE-HGF)0$$aShur, G.N.$$b21 000017014 7001_ $$0P:(DE-HGF)0$$aBelyaev, G.V.$$b22 000017014 7001_ $$0P:(DE-HGF)0$$aLaw, K.S.$$b23 000017014 7001_ $$0P:(DE-HGF)0$$aCairo, F.$$b24 000017014 773__ $$0PERI:(DE-600)2069847-1$$a10.5194/acp-11-5569-2011$$gVol. 11, p. 5569 - 5590$$p5569 - 5590$$q11<5569 - 5590$$tAtmospheric chemistry and physics$$v11$$x1680-7316$$y2011 000017014 8567_ $$uhttp://dx.doi.org/10.5194/acp-11-5569-2011 000017014 8564_ $$uhttps://juser.fz-juelich.de/record/17014/files/acp-11-5569-2011.pdf$$yOpenAccess 000017014 8564_ $$uhttps://juser.fz-juelich.de/record/17014/files/acp-11-5569-2011.gif?subformat=icon$$xicon$$yOpenAccess 000017014 8564_ $$uhttps://juser.fz-juelich.de/record/17014/files/acp-11-5569-2011.jpg?subformat=icon-180$$xicon-180$$yOpenAccess 000017014 8564_ $$uhttps://juser.fz-juelich.de/record/17014/files/acp-11-5569-2011.jpg?subformat=icon-700$$xicon-700$$yOpenAccess 000017014 8564_ $$uhttps://juser.fz-juelich.de/record/17014/files/acp-11-5569-2011.pdf?subformat=pdfa$$xpdfa$$yOpenAccess 000017014 909CO $$ooai:juser.fz-juelich.de:17014$$pdnbdelivery$$pVDB$$pVDB:Earth_Environment$$pdriver$$popen_access$$popenaire 000017014 9141_ $$y2011 000017014 915__ $$0LIC:(DE-HGF)CCBY3$$2HGFVOC$$aCreative Commons Attribution CC BY 3.0 000017014 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000017014 915__ $$0StatID:(DE-HGF)0010$$aJCR/ISI refereed 000017014 9131_ $$0G:(DE-Juel1)FUEK491$$aDE-HGF$$bErde und Umwelt$$kP23$$lAtmosphäre und Klima$$vAtmosphäre und Klima$$x0$$zvormals P22 000017014 9132_ $$0G:(DE-HGF)POF3-249H$$1G:(DE-HGF)POF3-240$$2G:(DE-HGF)POF3-200$$aDE-HGF$$bMarine, Küsten- und Polare Systeme$$lAtmosphäre und Klima$$vAddenda$$x0 000017014 9201_ $$0I:(DE-Juel1)IEK-7-20101013$$gIEK$$kIEK-7$$lStratosphäre$$x0 000017014 970__ $$aVDB:(DE-Juel1)131390 000017014 9801_ $$aUNRESTRICTED 000017014 9801_ $$aFullTexts 000017014 980__ $$aVDB 000017014 980__ $$aConvertedRecord 000017014 980__ $$ajournal 000017014 980__ $$aI:(DE-Juel1)IEK-7-20101013 000017014 980__ $$aUNRESTRICTED 000017014 981__ $$aI:(DE-Juel1)ICE-4-20101013