Update readme.md

data processing/readme.md

@@ -18,13 +18,18 @@ flag | meaning
 
 The file will be updated as new data come available. The content is:
 
-variable | description
-:--- | :---
-profile no. |	number of CTD cast
-niskin no.	| niskin bottle number
-sample no. | sample identifier as used on board
-latitude [deg N] | 
-longitude [deg E] | 
-Date UTC| 
-Time UTC	pressure [dbar]	QF	temperature [degC]	QF	salinity	QF	oxygen sensor [umol/kg]	QF	chl2_raw	QF	chlorophyll a (ug/L]	QF	potential density [kg/m3]	QF	oxygen titrated [mmol/kg]		turb_raw	QF	NO3 [µM/L]	QF	NO2 corr. [µM/L]		PO4 [µM/L]		SiO2 [µM/L]	
+variable | unit | description
+:--- | :--- | :---
+profile no. |	| number of CTD cast
+niskin no.	| | niskin bottle number
+sample no. | | sample identifier as used on board
+latitude | deg N | 
+longitude | deg E | 
+Date  | UTC |
+Time  | UTC |
+pressure | dbar | CTD pressure reading in dbar
+temperature | degC | CTD temperature reading
+salinity | | calculated CTD salinity
+oxygen sensor | µmol/kg | Oxygen concantration as recorded by the CTD sensor. The data are calibrated with Winkler titrated samples.
+chl2_raw	QF	chlorophyll a (ug/L]	QF	potential density [kg/m3]	QF	oxygen titrated [mmol/kg]		turb_raw	QF	NO3 [µM/L]	QF	NO2 corr. [µM/L]		PO4 [µM/L]		SiO2 [µM/L]