"ACE 1, Leg 2:   PMEL 2-stage impactor data collected onboard the Discoverer."

This is the text descriptor file for data contained in the file  L2IMP2_fin.csv.
Please contact Trish Quinn when using data (quinn@pmel.noaa.gov).

Ion concentrations are given in ng/m3.  Submicron values represent the ion concentration in all particles
with aerodynamic diameters < 1.0 um.  Supermicron values are for particles with aerodynamic diameters
> 1um and < 10 um.  Diameters are given for the relative humidity of the sampled air stream.

Uncertainties associated with the ion concentrations range from +/- 5 to 25%.

Columns in the spreadsheet are:

"1, Sample number"
"2, Start time,  GMT"
"3, Stop time,  GMT"
"4, Start Latitude"
"5, Stop Latitude"
"6, Start Longitude"
"7, Stop Longitude"
"8, average RH of the sampled air stream."
"9, standard deviation of the RH of the sampled air stream."
"10, volume of sample (m3 of air)"
"11, sub_Na, submicron Na concentration in ng/m3"
"12, sup_Na, supermicron Na concentration in ng/m3"
"13, sub_NH4, submicron NH4 concentration in ng/m3"
"14, sup_NH4, supermicron NH4 concentration in ng/m3"
"15, sub_K, submicron K concentration in ng/m3"
"16 sup_K, supermicron K concentration in ng/m3"
"17, sub_Mg, submicron Mg concentration in ng/m3"
"18, sup_Mg, supermicron Mg concentration in ng/m3"
"19, sub_Ca, submicron Ca concentration in ng/m3"
"20, sup_Ca, supermicron Ca concentration in ng/m3"
"21, sub_Cl, submicron Cl concentration in ng/m3"
"22, sup_Cl, supermicron Cl concentration in ng/m3"
"23, sub_Br, submicron Br concentration in ng/m3"
"24, sup_Br, supermicron Br concentration in ng/m3"
"25, sub_NO3, submicron NO3 concentration in ng/m3"
"26, sup_NO3, supermicron NO3 concentration in ng/m3"
"27, sub_tSO4,submicron total sulfate concentration in ng/m3"
"28, sup_tSO4, supermicron total sulfate concentration in ng/m3"
"29, sub_sSO4, submicron seasalt sulfate concentration in ng/m3"
"30, sup_sSO4, supermicron seasalt sulfate concentration in ng/m3"
"31, sub_nSO4, submicron non-seasalt sulfate concentration in ng/m3"
"32, sup_nSO4, supermicron non-seasalt sulfate concentration in ng/m3"
"33, sub_MSA, submicron MSA concentration in ng/m3."
"34, sup_MSA, supermicron MSA concentration in ng/m3."


Codes used in the file:

"M_Na_BB, Na concentration is below the blank value (< 210 ng / sample volume (m3))."
"M_NH4_BB, NH4 concentration is below the blank value (< 20 ng / sample volume (m3))."
"M_K_BB, K concentration is below the blank value (< 43 ng / sample volume (m3))."
"M_Mg_BB, Mg concentration is below the blank value (< 41 ng / sample volume (m3))."
"M_Ca_BB, Ca concentration is below the blank value (< 970 ng / sample volume (m3))."
"M_Cl_BB, Cl concentration is below the blank value (< 450 ng / sample volume (m3))."
"M_Br_BB, Br concentration is below the detection limit (< 8 ng / sample volume (m3))."
"M_NO3_BB, NO3 concentration is below the blank value (< 11 ng / sample volume (m3))."
"M_SO4_BB, SO4 concentration is below the blank value (< 140 ng / sample volume (m3))."
"T_Na_BB, Na concentration is below the blank value (< 350 ng / sample volume (m3))."
"T_NH4_BB, NH4 concentration is below the blank value (< 19 ng / sample volume (m3))."
"T_K_BB, K concentration is below the blank value (< 105 ng / sample volume (m3))."
"T_Mg_BB, Mg concentration is below the blank value (< 88 ng / sample volume (m3))."
"T_Ca_BB, Ca concentration is below the blank value (< 2700 ng / sample volume (m3))."
"T_Cl_BB, Cl concentration is below the blank value (< 580 ng / sample volume (m3))."
"T_Br_BB, Br concentration is below the detection limit (< 30 ng / sample volume (m3))."
"T_NO3_BB, NO3 concentration is below the blank value (< 88 ng / sample volume (m3))."
"T_SO4_BB, SO4 concentration is below the blank value (< 190 ng / sample volume (m3))."