Index of /ftp/ndp005a

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[DIR]Parent Directory  -  
[   ]spo_co2.zip18-Oct-2011 15:15 1.4M 
[   ]spo_co2.tar.gz18-Oct-2011 15:15 1.4M 
[DIR]spo/04-Jun-2013 15:15 -  
[   ]spo.zip18-Nov-2014 15:15 1.7M 
[   ]spo.tar.gz18-Nov-2014 15:15 1.7M 
[   ]spo.in-situ.zip25-Sep-2007 15:15 1.2M 
[   ]spo.in-situ.tar.gz13-Sep-2005 15:15 1.2M 
[   ]spo.in-situ.tar.Z25-Sep-2007 15:15 1.4M 
[   ]smo_co2.zip18-Oct-2011 15:15 1.7M 
[   ]smo_co2.tar.gz18-Oct-2011 15:15 1.7M 
[DIR]smo/04-Jun-2013 15:15 -  
[   ]smo.zip18-Nov-2014 15:15 2.0M 
[   ]smo.tar.gz18-Nov-2014 15:15 2.0M 
[   ]smo.in-situ.zip25-Sep-2007 15:15 1.4M 
[   ]smo.in-situ.tar.gz13-Sep-2005 15:15 1.3M 
[   ]smo.in-situ.tar.Z25-Sep-2007 15:15 1.6M 
[   ]mlo_co2.zip18-Oct-2011 15:15 1.9M 
[   ]mlo_co2.tar.gz18-Oct-2011 15:15 1.9M 
[DIR]mlo/04-Jun-2013 15:15 -  
[   ]mlo.zip18-Nov-2014 15:15 2.2M 
[   ]mlo.tar.gz18-Nov-2014 15:15 2.2M 
[   ]mlo.in-situ.zip25-Sep-2007 15:15 1.6M 
[   ]mlo.in-situ.tar.gz13-Sep-2005 15:15 1.6M 
[   ]mlo.in-situ.tar.Z25-Sep-2007 15:15 1.8M 
[   ]brw_co2.zip18-Oct-2011 15:15 1.9M 
[   ]brw_co2.tar.gz18-Oct-2011 15:15 1.9M 
[DIR]brw/04-Jun-2013 15:15 -  
[   ]brw.zip18-Nov-2014 15:15 2.2M 
[   ]brw.tar.gz18-Nov-2014 15:15 2.2M 
[   ]brw.in-situ.zip25-Sep-2007 15:15 1.6M 
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[   ]brw.in-situ.tar.Z25-Sep-2007 15:15 1.8M 
[TXT]Update_notes18-Oct-2011 15:15 5.4K 

CONTINUOUS IN-SITU CO2 DATA FILES

National Oceanic and Atmospheric Administration (NOAA)
Climate Monitoring and Diagnostics Laboratory (CMDL)
Carbon Cycle Greenhouse Gases Group (CCGG)

Version: 2005-09-15
************************************************************

These directories contain atmospheric CO2 dry-air mole
fractions from the 4 NOAA CMDL observatories: Barrow, Alaska
(BRW), Mauna Loa, Hawaii (MLO), American Samoa (SMO), and
South Pole (SPO).

Correspondence concerning these data should be
directed to:

	Dr. Pieter Tans
	Group Chief, Carbon Cycle Group
	NOAA/CMDL
	R/CMDL1
	Boulder, CO 80305

 or 	Kirk Thoning
	NOAA/CMDL
	R/CMDL1
	Boulder, CO 80305

or by electronic mail at

	pieter.tans@noaa.gov
 or	kirk.w.thoning@noaa.gov

**************************************************************************
USE OF DATA

These data are made freely available to the public and the
scientific community in the belief that their wide dissemination
will lead to greater understanding and new scientific insights.
The availability of these data does not constitute publication
of the data.  CMDL relies on the ethics and integrity of the user to
assure that CMDL receives fair credit for their work.  If the data
are obtained for potential use in a publication or presentation,
CMDL should be informed at the outset of the nature of this work.
If the CMDL data are essential to the work, or if an important
result or conclusion depends on the CMDL data, co-authorship may
be appropriate.  This should be discussed at an early stage in
the work.  Manuscripts using the CMDL data should be sent to CMDL
for review before they are submitted for publication so we can
insure that the quality and limitations of the data are accurately
represented.

--------------------------------------------------------------------
RECIPROCITY

Use of these data implies an agreement to reciprocate.
Laboratories making similar measurements agree to make their
own data available to the general public and to the scientific
community in an equally complete and easily accessible form.
Modelers are encouraged to make available to the community,
upon request, their own tools used in the interpretation
of the CMDL data, namely well documented model code, transport
fields, and additional information necessary for other
scientists to repeat the work and to run modified versions.
Model availability includes collaborative support for new
users of the models.

--------------------------------------------------------------------
WARNINGS

Every effort is made to produce the most accurate and precise
measurements possible.  However, we reserve the right to
correct the data based on recalibration of standard gases
or for other reasons deemed scientifically justified.

We are not responsible for results and conclusions based on use
of these data without regard to this warning.

Please send comments to the e-mail address given above.

***************************************************************************
UPDATES

Please read the 'Update_notes' file for information regarding problems 
and changes to the data sets.

***************************************************************************
STATION INFORMATION

Site                                                                  Elevation
Code   Site                       Country            Lat      Long     (meters)
_______________________________________________________________________________
BRW  Point Barrow, Alaska          U.S.              71 19'N 156 36'W      11 
MLO  Mauna Loa, Hawaii             U.S.              19 32'N 155 35'W    3397 
SMO  American Samoa                U.S. Territory    14 15'S 170 34'W      30 
SPO  Amundsen Scott (South Pole)   Antarctica        89 59'S  24 48'W    2810 

***************************************************************************
DATA ACCESS

All data files are text files.

In addition to the text files found in each directory, there are 2
compressed tar files and 2 zipped files that contain all the files
in the corresponding directory, e.g. brw.in-situ.tar.Z and
brw.in-situ.zip contains all the files in the directory 'brw'.
To transfer all the files in a directory, it is more efficient to download
the tar or zipped files.  To transfer the tar files, use the following steps
from the ftp prompt:

1. ftp>	binary                     ! set transfer mode to binary
2. ftp>	get brw.in-situ.tar.Z      ! transfer the file
3. ftp> bye                        ! leave ftp
4. $ uncompress brw.in-situ.tar.Z  ! uncompress your local copy
5. $ tar xvf brw.in-situ.tar       ! unpack the file

This will create a directory called 'brw' and place each of the
files in this directory.  Repeat the steps for each tar file.

To transfer the zipped files to your local system follow steps 1 - 3
(above) and then "unzip."

**************************************************************************
FILE NAME DESCRIPTION

Encoded into each file name is the sampling location, platform, and
strategy; measurement laboratory; file content; and gas identifier.
All file names use the following naming scheme:

 1     2               3     4         5          6           7
[site][data grouping]_[lab#][strategy][platform]_[qualifier].[gas]

1. [Sampling site]
   (ex) brw_, mlo_

2. [Grouping of data within the file]

   (ex) brw1998_, mlo2003_

3. [Measurement laboratory]

   A two character numeric field identifies the measurement laboratory (01-99).
   NOAA CMDL is lab number 01.

4. [Sampling strategy]

   A single alphanumeric character (0-9,a-z,A-Z) indicates the sampling strategy.

   _??D               Discrete
   _??C               Semi-continuous

5. [Sampling platform]

   A single alphanumeric character (0-9,a-z,A-Z) indicates the sampling platform.

   _???0              Single Fixed Position
   _???1              Ship
   _???2              Aircraft
   _???3              Tower

6. [Qualifier]

   An alphanumeric string describes the type of data included in the file.

   _????_event        Data from every collection event
   _????_mm           Computed monthly mean values
   _????_hr           Computed hourly averages (semi-continuous data only)
   _????_day          Computed daily averages (semi-continuous data only)

7. [Gas]

   Identifies the trace gas species.

   _????_???.co2      Carbon dioxide
   _????_???.ch4      Methane
   _????_???.co2c13   d13C (co2)

*****************************************************************************
HOURLY AVERAGE DATA FILES 

Data files are located in "/ccg/co2/in-situ/[site]/".  The hourly averaged
data are grouped by year (e.g., mlo1998_01C0_hr.co2).

The data files contain multiple lines of header information followed
by one line for each hour.  Each line includes the

SITE CODE, YEAR, MONTH, DAY, HOUR, MEAN VALUE, STD, and QC FLAG.

Fields are delimited by whitespace.

(ex)    MLO 1999 01 01 16   367.17   0.06 ...

Fields are defined as follows:

    [SITE CODE]  The three-character sampling location code (see above),

    [YEAR, MONTH, DAY, HOUR]  The year, month, day, and hour in UTC,

    [MEAN VALUE]  CO2 mole fraction in umol/mol (ppm), missing values
     denoted by -999.99,

    [STD]  Standard deviation of mean value (1 sigma),

    [QC FLAG]  A three character field indicating the results of our
     selection process, described below.

Missing data will have a value of -999.99 for the mixing ratio.  
Times are specified in Greenwich Mean Time. Hours are specified 
as the beginning of the hour, for example, hour 5 corresponds to 
5 AM to 6 AM GMT.

The selection process is done to distinguish "background" mixing
ratios, that is, the values that we believe are not contaminated 
by local sources or sinks of CO2.  The selection process depends 
on the station (see references).  There are a large number of 
possible codes, but the most common codes are:

   ... - No code applied. Data is considered 'background'.
   C.. - Weekly calibration of reference gases, no data available
   I.. - Instrument malfunction, no data available
   .V. - Large variability of CO2 mixing ratio within one hour
   .D. - Hour-to-hour difference in mixing ratio > 0.25 ppm
   .A. - Automatic selection based on residuals from a spline curve
   .U. - Rejected, diurnal variation (upslope) in CO2 (Mauna Loa only)

Other codes may be used, but the main point is that missing data 
will have a value of -999.99 for the hour, and "background" values 
will be designated by a lack of a code.  See also the 'Update_notes' 
file for information regarding other codes.

**************************************************************************
DAILY MEAN DATA FILES

Data files are located in "/ccg/co2/in-situ/[site]/".  There is one
daily mean data file for each site (e.g., brw_01C0_day.co2).  The
file contains one row for each day in the reporting period.

Missing data have a value of -999.99 for the mixing ratio, -9.99
for the standard deviation, and 0 for the number of hours.  The
daily averages are based on only those hourly averages deemed to
be "background" values.

The data files contain multiple lines of header information 
followed by one line for each day.

Each line includes the
	
SITE CODE, YEAR, MONTH, DAY, MEAN VALUE, STD, and HOURS INCLUDED  
IN DAILY MEAN.

Fields are delimited by whitespace.

(ex) MLO 1999  1  9   367.48  0.14 16

Fields are defined as follows ...

	[SITE CODE]  The three-character sampling location code (see above),

	[YEAR, MONTH, DAY]  The year, month, and day in UTC,

	[MEAN VALUE]  Computed mean CO2 value in umol/mol (ppm),

	[STD]  Standard deviation of mean value (1 sigma),

	[NUMBER HOURS]  The number of hourly averages used to calculate
         the daily mean.

**********************************************************************
MONTHLY MEAN DATA FILES

Data files are located in "/ccg/co2/in-situ/[site]/".  There is one
monthly mean data file for each site, (e.g., mlo_01C0_mm.co2).  Monthly 
averages are computed from the daily averages.  Missing daily averages 
are skipped.

Missing data has -999.99 for the mixing ratio.

The data files contain multiple lines of header information followed
by one line for each available month.

Each line includes the 

SITE CODE, YEAR, MONTH, MEAN VALUE, STD, and DAYS INCLUDED
IN MONTHLY MEAN. 

Fields in each line are delimited by whitespace.

(ex) MLO 1999  1   367.94  0.57 27

Fields are defined as follows ...

	[SITE CODE]  The three-character samplng location code (see above),

        [YEAR, MONTH]  Year and month,

        [MEAN VALUE]  Computed mean CO2 value in umol/mol (ppm),

	[STD]  Standard deviation of mean value (1 sigma).

	[NUMBER DAYS]  The number of daily averages used to calculate
         the monthly mean.

**********************************************************************
REFERENECES:

Peterson, J.T., W.D. Komhyr, L.S. Waterman, R.H. Gammon, K.W.
   Thoning, and  T.J. Conway, Atmospheric CO2 variations at Barrow,
   Alaska, 1973-1982,  J. Atmos. Chem., 4, 491-510, 1986.

Herbert, G.A., E.R. Green, J.M. Harris, G.L. Koenig, S.J. Roughton,
   and K.W. Thaut, Control and monitoring instrumentation for the 
   continuous measurement of atmospheric CO2 and meteorological 
   variables, J. Atmos. Oceanic Technol., 3, 414-421, 1986.

Gillette, D.A., W.D. Komhyr, L.S. Waterman, L.P. Steele, and R.H.
   Gammon, The NOAA/GMCC continuous CO2 record at the South Pole,
   1975-1982, J. Geophys. Res., 92, 4231-4240, 1987.

Halter, B.C., Harris, J.M., and Conway, T.J., Component signals in
   the record of atmospheric carbon dioxide concentation at
   American Samoa, J. Geophys. Res., 93, 15914-15918, 1988.
                 
Komhyr, W.D., T.B. Harris, L.S. Waterman, J.F.S. Chin, and K.W.
   Thoning,  Atmospheric carbon dioxide at Mauna Loa Observatory: 1.
   NOAA Global Monitoring for Climatic Change measurements with a
   nondispersive infrared analyzer, 1974-1985, J. Geophys. Res.,
   94, 8533-8547, 1989.
           
Thoning, K.W., P.P. Tans, and W.D. Komhyr, Atmospheric carbon
   dioxide at Mauna Loa Observatory, 2. Analysis of the NOAA/GMCC
   data, 1974-1985., J. Geophys. Res. ,94, 8549-8565, 1989.

Thoning, K.W. Selection of NOAA/GMCC CO2 data from Mauna Loa
   Observatory, In The Statistical Treatment of CO2 Data
   Records, NOAA Tech. Mem. (ERL-ARL-173), Environ. Res. Lab.,
   131 pp., 1989

Waterman, L.S., D. W. Nelson, W.D. Komhyr, T.B. Harris, and K.W.
   Thoning,  Atmospheric carbon dioxide measurements at Cape
   Matatula, American Samoa, 1976-1984., J. Geophys. Res. , 94,
   14817-14829, 1989.