***************************************
*****Last revised on Jan 31, 2015*****
***************************************

Nephelometer and PSAP data processing and corrections for GO-Amazon-I Campaign (Feb-Mar 2014). 
For more details on GO-Amazon field campaign visit: http://www.arm.gov/campaigns/aaf2014amazon

Data Column Header (total 16 columns):

Time hh mm ss tbs_tr_corr tgs_tr_corr trs_tr_corr bbs_tr_corr bgs_tr_corr brs_tr_corr 
tba_corr tga_corr tra_corr neph_P neph_T neph_R
  
Time:			Time in UT
hh:			hour (All Time in UT)
mm: 			minute
ss:			second
tbs_tr_corr:		Corrected total scattering coefficient at 450nm (Mm^-1)
tgs_tr_corr:		Corrected total scattering coefficient at 550nm (Mm^-1)
trs_tr_corr:		Corrected total scattering coefficient at 700nm (Mm^-1)
bbs_corr:		Corrected back scattering coefficient at 450nm  (Mm^-1)
bgs_corr:		Corrected back scattering coefficient at 550nm  (Mm^-1)
brs_corr:		Corrected back scattering coefficient at 700nm  (Mm^-1)
tba_corr:		Corrected absorption coefficient at 461.6 nm (Mm^-1)
tga_corr:		Corrected absorption coefficient at 522.7 nm (Mm^-1)
tra_corr:		Corrected absorption coefficient at 648.3 nm (Mm^-1)
neph_P:			Pressure in Nephelometer (mb)
neph_T:			Temperature in Nephelometer (oC)
neph_R: 		Relative Humidity in Nephelometer (%)

Notes: 

# The start and end time of nephelometer and PSAP data are matched as per the 
timing provided by the file at IOPShare 
'/var/ftp/goamazon/incoming/aaf-goamazon-final/Neph_PSAP'
 
# The Nephelometer and PSAP data are corrected based on methods discussed 
in Anderson and Ogren 1998, Bond et al 1999.

# Calibrations of Nephelometer are performed using zero (particle free) 
air, CO2 and SF6 gases.

# Spot sizes of PSAP are measured from the filters loaded in Go-Amazon-I field 
campaign as well as from lab experiments at PNNL.

# Flow calibrations of PSAP are performed in Go-Amamzon field campaign as well 
as from lab experiments at PNNL.
 
# There are some events when PSAP showed unexpected behavior when RH 
changed suddenly/drastically (e. g. in presence of clouds). To our 
knowledge the PSAP response to RH is unknown. Screening is applied 
to minimize this behavior. Some additional screening may be needed 
using cloud and meteorological properties, which is under consideration.

If you have any question, comments concerns or want use this data set, 
please contact Duli Chand (Duli.Chand@pnnl.gov) and Beat Schmid (Beat.Schmid@pnnl.gov).
If the data are used in a formal publication an offer of 
co-authorship should be extended to the aforementioned individuals.

References:
Anderson, T. L.,and J. A. Ogren, Determining aerosol radiative properties 
using the TSI-3563 integrating nephelometer, AerosolSci.Technol.,29,57–69,1998.

Bond, T. C., T. L. Anderson, and D.Campbell, Calibration and intercom-parison 
of filter-based measurements of visible light absorption by aerosols, 
Aerosol Sci.Technol.,30,582–600,1999.

Ogren, J. A. (2010), Comment on "Calibration and Intercomparison of 
Filter-Based Measurements of Visible Light Absorption by Aerosols", 
Aerosol Science and Technology, 44(8), 589-591, 10.1080/02786826.2010.482111