README file for cleaned, 1-minute CN data files collected aboard the RH Brown during
the ACE-Asia cruise. These data are preliminary and intended to help investigators 
reduce their own data.

If you have any questions regarding this file, please contact 
Derek Coffman (derek@pmel.noaa.gov) or Tim Bates (bates@pmel.noaa.gov).

The file contains: 
  - 3 time columns: 
  	DOY = Day of Year (e.g. 1200 on Feb 1, 2001 = 32.5)
  	hr  = hour of the day (0-23)
  	min = minute of the hour (0-59)

  - 2 position columns:
  	ShipLat  = Latitude from the RH Brown's data system (positive values depict degrees N)
  	ShipLong = Longitude from the RH Brown's data system (positive values depict degrees E)

  - 3 CN columns for data cleaned at Level1:
  	UFCN_level1 = particle concentration as measured by TSI 3025 
  	CN-stack_level1 = particle concentration as measured by TSI 3760 
  	CN-Direct_level1 = particle concentration as measured by TSI 3760 

	* all 3 CN counters were on the same sampling line
	
  - 3 CN columns for data cleaned at Level2:
    these are the same as Level1, but with more data points removed as explained below

  - 2 relative wind columns:
  	RelativeWndS = relative wind speed as measured by PMEL anemometer (in m/s)
  	RelativeWndD = relative wind direction as measured by PMEL anemometer - positive values
  	               indicate winds from starboard side, negative from the port side, and 0 
  	               indicates winds from straight ahead (referenced to the bow of the ship)
  	               
These data have been cleaned at 2 levels:	
  - Level 1: remove all data during times which the instruments were not working including	
	* instrument malfunction / not operating
	* flow checks / BuOH fill / maintenance
	* times when blower was reversed (usually when it was known that the relative wind would be
	  from behind)
	
	
  - Level 2: remove all data that have ship contamination from the RH Brown based on:	
	* relative winds 
	* SO2 and O3 levels
	

Data that are missing or have been removed are shown as -999