Royal Netherlands Meteorological Institute Ministry of Infrastructure and

Royal Netherlands Meteorological Institute Ministry of Infrastructure and Environment An update on the NO 2 sonde Ankie Piters, Marc Allaart, Wesley Sluis, Wytze Lenstra, KNMI

ESA’s Innovation Triangle Innitiative “Programme to foster the introduction of breakthrough innovations and technologies for space applications. “ Purpose is to make the NO 2 sonde ready for serial production: - improve the calibration procedure - improve the design - transfer the knowledge to industry Cooperation with GRAW radiosondes to produce the sonde Duration of this project: 15 months External reviewer/advisor: Michel Van Roozendael, BIRA Aim: user evaluation model end 2013, GRAW product end 2015

MAXDOAS retrievals 25 June NO 2 sonde 25 June Picture from Folkard Wittrock, IUPB

What happened after CINDI? winter De Bilt, the Netherlands November 2010 – February 2011 9 flights DISCOVER-AQ Baltimore / Washington, USA July 2011 8 flights PEGASOS Cabauw, the Netherlands May 2012 7 flights + 7 ground sondes

DISCOVER-AQ campaign 2011, USA profile measured during aircraft descend, 20 July NO 2 sonde CRDS aircraft and tethered balloon measurements thanks to: Russ Dickerson (UMD) and Richard Clark (Millersville Univ)

PEGASOS campaign May 2012, Netherlands Zeppelin Weather balloon 2 MAX-DOAS-ses NOx analyser Marc and Ankie with 2 sondes

On-ground comparisons with NOx analyser (BLC) ~500 m distance side-by-side measurement RIVM NOx analyser NO 2 sonde 1 min. average of NO 2 sonde data: Lou Gast, RIVM Sensitivity of luminol increases with time bottle #1 bottle #2 #3

1200 m AQ model (H. Elbern, Univ. Cologne) 500 m 0 m 27 -5 -2012 6: 00 7: 00 8: 30 9: 45

Comparing with models model data: Henk Eskes and Patricia Castellanos, KNMI

24 h backtracjectory 7 Dec, 8: 00 UT, 1 km NO 2 above BL 6 Dec, 15: 00 UT NO 2 profiles along trajectorie

Next steps What determines/affects sensitivity? Optimise design Optimise calibration procedure Transfer knowledge to GRAW radiosondes And also: Analyse DISCOVER-AQ and PEGASOS data Demonstrate the use for: Model evaluation MAX-DOAS interpretation Satellite validation

Chasing the sondes during PEGASOS