Data Processing:
Filter blanks were processed in the same way as samples but were below method detection limits. Reported soluble aerosol major ion concentrations values have been normalized to the volume of air filtered during sample collection. Each sample collection period produced 36 replicate filters. Three of those filters were leached with ultrapure deionized water (DI water) and a subsample from one of these for each deployment was analyzed for major ion concentrations. To assess measurement precision, a subset of samples were analyzed multiple times, from which a relative standard deviation was determined for each major ion species. The standard deviations in the datasheet represent application of these RSDs to all samples. Detection limits are defined as three times the standard deviation from replicate analyses of low concentration samples. Data are marked as described in the datasheet.

Known Problems/Issues:
AEROS2 (Event 6546) was not analyzed due to exceptional contamination of the collection filters with sea spray.
The K+ data were frequently below method detection limit.

Quality Flags:
Quality flags have been applied with the following definitions:
0 = No quality control;
1 = Good value;
2 = Probably good value;
3 = Probably bad value;
4 = Bad value;
5 = Value changed;
6 = Value Below Detection;
7 = Value in excess;
8 = Interpolated value;
9 = Missing value.

Detection Limits:
Detection limit used is 3xSD of triplicate analyses of the lowest measurable sample. All filter blanks were below detection limit for all major ions. Reported detection limits were not normalized by air volume and sample data were evaluated relative to the method detection limit prior to the normalization step in data processing. Data below the detection limit are flagged with code 6 and no value reported ("nd"). Detection limits are reported in the attached Supplemental File (PDF).

Note on Standard Deviations:
Only one major ion sample generated per aerosol deployment. A handful of samples were analyzed multiple times, from which a relative standard deviation (%) for each chemical species was determined and this was applied to all values.

BCO-DMO Processing:
- renamed fields;
- added date/time fields in ISO8601 format and removed original day, month, year, and time columns.

SMLH2O_Aerosol_Ions_Leg1.csv