NOxy Measurements at Hohenpeissenberg Meteorological Observatory

Transcription

1 German Meteorological Service Hohenpeissenberg Meteorological Observatory NOxy GAW Workshop September, 8-9, Hohenpeissenberg NOxy Measurements at Hohenpeissenberg Meteorological Observatory Stefan Gilge 1

2 German Meteorological Service Hohenpeissenberg Meteorological Observatory GAW Monitoring Programme at Hohenpeissenberg Observatory Aerosol Characteristics: Physical: mass (TSP, PM-10), number (> 3 nm, > 11 nm), size distribution (13 nm 32 µm) Optical: scattering, absorption (BC), turbidity, optical depth, backscatter coefficient profile Chemical: Impactor (4 size classes), IC-analysis Precipitation: ph, electrical conductivity, kations, anions, heavy metals. Meteorology: full set of data, backward trajectories. Trace Gases: CO 2, CH 4, SF 6 (NOAA flask sampling) O 3, SO 2, CO, NO, NO 2, NO y,, PAN, NH 3, H 2 O 2, 222 Rn VOC: light, heavy, biogenic, oxygenated OH, H 2 SO 4. NO 2 profile (U.Heidelberg) Solar Radiation: Global, diffuse, IR, UV-B, Photolysis frequencies j(no 2 ) and j(o 1 D). Ozone (O 3 ): ambient, vertical profile with ozone sonde and Lidar (troposphere and stratosphere), total ozone (Dobson and Brewer). 2

3 NO xy at MOHp IN stainless steel PLC CLD 1 LDL 15 ppt MB CLD 2 50 ppt IN PFA teflon PLC CLD 3 50 ppt Mo-Converter blue light -converter CLD 4 PAN - GC MaxDOAS 50 ppt 15 ppt test phase 3

4 QA/QC procedures redundant measurements storage of all data including metadata use of station logbook and calibration forms (paper and excel sheet) calibration: every 2 nd day at zero and 30 ppb NO zero air: ECO Physics PAG 003 or synthetic air in cylinder _working standards with 5, 10, 100 ppm and dynamical dilution by MFC _station s standard: NIST #195524SG, 9.94 ppm NO in N 2 NO 2 by gas phase titration (Environics S 100, ansyco for low mixing ratios) NO y routinely once a week as NO 2, additionally with HNO 3 permeation _source (first years: self built, but unstable, now: VICI, test phase) Check of inlet line losses First years of measurement: Luminox LMA-4 as backup instrument and for _comparison reasons, but: too expensive, lot of data losses Plausibility checks with other trace gases: Ozone, CO, particles,. Intercomparisons with other groups: FZJ, DLR, MPI, 4

5 Intercomparisons (I) Comparison among CLD s ambient air, each with own standard gas Intercomparison NO : DLR - MOHp NO : y = x R² = 0.93 NO (MOHp) [ppb] NO 2 : y = x R² = 0.96 NO y : y = x R² = NO (DLR) [ppb] 5

6 Results: NO xy Time Series NO monthly mean NO2 monthly mean NOy monthly mean 12 month r.m. NO2 12 month r.m. NOy 12 month r.m. NO NO, NO2, NOy (ppb)

7 trend for different wind sectors overall no trend is detectable 2 wind directions: WSW rural background and NE moderately polluted insignificant increase at NE and significant decrease at WSW % % 8% % 4% 2% 0% NOx [ppb] NOx WSW NOx NOx NE R 2 = R 2 = R 2 =

8 mean annual variation NO NO2 NOy NO WSW NO2 WSW NOy WSW NO NE NO2 NE NOy NE NO, NO2, NOy [ppb] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 8

9 mean diurnal variation NE, winter NOx [ppb] WSW, winter 2 1 NE, summer WSW, summer time of day 9

10 German Meteorological Service Hohenpeissenberg Meteorological Observatory Thanks for your attention! Photo: Claudia Hinz 10