6/19/2015
1
Ambient Intercomparisons to Evaluate AMS Concentrations
Including OA
Jose-Luis Jimenez et al.University of Colorado-Boulder
6th AMS Clinic – Boulder, 18-June-2015
Volume conc. AMS vs 2 SMPS @ SOAS-2013
Non-AMS for
everything
Hu et al.In prep. 2015
6/19/2015
2
Washenfelder et al. GRL 2015 http://onlinelibrary.wiley.com/doi/10.1002/2014GL062444/epdf
Validation of SMPS+AMS vs Extinction
Volume conc. comparison to two SMPS in CU @ SOAS
Hu et al.In prep. 2015
6/19/2015
3
Mexico City 2006: Aircraft Intercomp.
DeCarlo et al.ACP 2008
AMS vs Sunset and 14C Filter OA at SOAS-2013
Hu et al.In prep. 2015
6/19/2015
4
Comparison to 2 Sunset OC – Riverside 2005
• No apparent trend in ratios with time of the day
Docherty et al.ACP 2011
Uncertainty Analysis of Field Data
Bahreini et al. JGR 2009
6/19/2015
5
Hygroscopic Growth as a Constraint in FOA
Attwood et al., 2014: http://onlinelibrary.wiley.com/doi/10.1002/2014GL061669/pdf
5 SMPSs in the field (As shown at 2011 AMS Users Mtg)
10
Num
ber
Con
cent
ratio
n
Factor of x5 between instrumentsNone of SMPS agree with CPC!
6/19/2015
6
SO4 Intercomparison in Field
An important uncertainty in most situations
2AMS = 2
CE + 2RIE + 2
user
• User-introduced errors- Errors in IE cals- Errors in single SMPS, scaling to it- Errors in software processing- Problems w/ lens or inlet- Problems w/ DAQ threshold- Other problems- This is an important reason why we have Clinics!
• Recommend “Best IE cal practices,” CDCE, no scaling!
