AN IGOR TOOL FOR GEOGRAPHICAL ORIGINS

Transcription

1 ZEFIR AN IGOR TOOL FOR GEOGRAPHICAL ORIGINS

2 WHY? If answering «what are the sources?» is crucial, answering «where do they come from?» is just as much important! receptor approaches : WIND or BACKTRAJECTORIES Wind analyses are best for sources within a relatively short geographical range. As wind measured at the receptor site is not necessarily representative of the global origin of the air mass, it is not very precise for long-range advected pollution. Trajectory analyses are best for long-range pollution. They conceptually fail to provide meaningful information for local sources. Need of a tool which performs both!

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4 Your data, in one glance

5 Filtering input data by: concentration (min/max) temporal thresholds external variable (min/max) manual threshold auto. percentile calculation Seasons Customized temporal window DJF / MAM / JJA / SON

6 Which kind of data? Any kind of atmospheric variables that you want to investigate Ambient concentrations Source apportionment results

7 Which kind of data? Built-in import for source apportionment with P.E.T. and SoFi!

8 WIND ANALYSIS NWR SWIM SWIM-2 Pollution Rose Various methodologies available

9 WIND ANALYSIS NWR SWIM SWIM-2 Pollution Rose Non-Parametric Regressions C i : concentration at t i W i : wind direction at t i Y i : wind speed at t i K : Gaussian Kernel K 2 : Epanechnikov Kernel In the case of NWR, sigma & h are constant In the case of SWIM, sigma & h are time dependent (respectively wind direction and wind speed standard deviation) In the case of SWIM-2, h is constant, and sigma is time dependent (depends on wind speed, and wind direction standard deviation)

10 WIND ANALYSIS NWR SWIM SWIM-2 Pollution Rose Non-Parametric Regressions

11 WIND ANALYSIS NWR SWIM SWIM-2 Pollution Rose Non-Parametric Regressions Openair concentration (µg/m 3 )

12 WIND ANALYSIS NWR SWIM SWIM-2 Pollution Rose Regular pollution roses

13 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster

14 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Explore backtrajectories Date/time Altitude Concentration

15 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Temporal extension of the dataset

16 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster i n ij : in cell where endpoint falls j measuring site endpoint m ij : PSCF : in cells if C l >C crit CWT : C l in cells at each endpoint CF : log(c l ) in cells 2 2

17 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Trajectory cut-off «Cut» each trajectory if : it rained if altitude is too high discarded endpoints discarded endpoints Avoid meaningless endpoints

18 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Weighing functions Regular discrete function Sigmoid function Only 3 parameters to set!

19 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Result map Trajectory density map concentration (ppb) trajectory density

20 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Re-weight panel!

21 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Combines N trajectory analyses :

22 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster Grouping backtrajectories following similar pathways

23 TRAJECTORY ANALYSIS PSCF CWT CF Multi-site Cluster ZeFir uses scripts from HYSPLIT to calculate clusters. But ZeFir automatically load, process and display the results Mean clusters Timeserie Stat. distrib. by cluster

24 TRAJECTORY ANALYSIS If you don t have backtrajectories, ZeFir offers the possibility to control HYSPLIT software directly within Igor through a simplified panel. Instead a one-month calculation with HYSPLIT, a whole year (even several years) can be calculated with ZeFir. Only GDAS met files can be used so far

25 GRAPH CONTROL You don t like the graph settings? Well change them is made very easy! Change colorbar Change colorscale

26 RE-PLOT You may loose your memory, but ZeFir won t! ZeFir stores each result in a specified folder.... and keeps track of what you are doing Any saved result can be instantaneously re-plotted

27 More info at

28 More info at Petit et al. (207), Environmental Modelling & Software