File naming conventions
Data files are stored under the “tropac” subdirectory on the NIWA anonymous FTP site in a series of sub-directories classified first by gas species and then by sampling site or platform (aircraft, ship, etc).
Subfolders for different species are as follows:
|
aerosols |
currently empty, but will contain aerosol data |
|
ch4 |
methane data |
|
co |
carbon monoxide data |
|
co2 |
carbon dioxide data |
|
mdl |
currently empty but will contain computer model results and code |
|
nmhc |
Non-methane hydrocarbon data (C2H2, C2H4, C2H6, C3H6, C3H8, C6H6, C6H7, iC4H10, nC4H10, iC5H12, nC5H12 ) |
|
n2o |
nitrous oxide data |
|
o2 |
currently empty but will contain oxygen data |
|
o3 |
surface ozone data |
|
papers |
reports and publications available for downloading |
At the next level down subfolders for different sites or platforms are currently as follows:
|
arh |
Arrival Heights (Scott Base), Antarctica |
|
bhd |
Baring Head clean air station |
| lau | Lauder atmospheric research station |
|
pac |
Sampling across the Pacific Ocean on Blue Star Line ships (BSL) between New Zealand and the United States, and Fuji TransWorld (FTW) ships between New Zealand and Japan. |
|
suv |
University of the South Pacific, Suva, Fiji |
Data files follow a naming convention as follows:
The filename prefix is the site or platform code as above and generally duplicates the subdirectory name. For large amounts of data, the filename prefix also specifies a date range or release date (e.g. for hourly data separated by year this could be “1990”, “1991” etc.).
For measurement/sample data, the file extension specifies the gas species measured, and can also specify the measurement technique as follows:
|
code |
Species |
Measurement |
Units |
|
co2nd |
Carbon dioxide |
NDIR |
ppm |
|
co2gc |
Carbon dioxide |
GC |
ppm |
|
co2d13 |
Carbon dioxide |
d13C |
dimensionless ‰ |
|
co2d14 |
Carbon dioxide |
D14C |
dimensionless ‰ |
|
ch4 |
Methane |
GC |
ppb |
|
ch4d13 |
Methane |
d13C |
dimensionless ‰ |
|
ch4d14 |
Methane |
D14C |
dimensionless ‰ |
|
Co_m |
Carbon monoxide |
Manometric |
ppb |
|
Co_g |
Carbon monoxide |
GC |
ppb |
|
cod13 |
Carbon monoxide |
d13C |
dimensionless ‰ |
|
cox14 |
Carbon monoxide |
14CO molec/cc(STP) |
number density |
|
dicma |
Sea water dissolved inorganic carbon |
Manometric (extraction line) |
µmole/kg-seawater |
|
n2o |
Nitrous oxide |
GC |
ppb |
|
o3 |
Surface ozone |
UV photometry |
ppb |
A file extensions .mts is for monthly series (i.e. interpolated values for mid-point of each month)
File formats
Unless noted otherwise in “readme.txt” files, data files are ASCII text files organised as columns of data with one or more spaces as column separators. The standard format used for “grab sampling” is as follows:
|
Field |
width |
example |
|
|
platform/ site code |
3 |
BHD |
|
|
Sampling time (start of) |
|||
|
year |
4 |
1989 |
|
|
month |
2 |
11 |
|
|
day |
2 |
27 |
|
|
hour |
2 |
13 |
|
|
minute |
2 |
43 |
|
|
Sampling location |
|||
|
latitude (decimal degrees) |
6 |
-41.42 |
|
|
longitude (decimal degrees) |
7 |
174.87 |
|
|
altitude (m) |
5 |
85 |
|
|
Result |
|||
|
value |
7 |
1745.1 |
|
|
error |
6 |
4.2 |
|
|
Flags |
|||
|
sampling conditions flag |
1 |
2 |
|
|
collection/ storage flag |
1 |
0 |
|
|
measurement flag |
1 |
1 |
|
|
other |
|||
|
sampling duration (min) |
5 |
1 |
|
|
(unique) sample-ID |
6 |
G1847 |
|
|
analysis-ID (optional) |
12 |
891214/56 |
|
|
wind speed (m/s) |
3 |
22.1 |
|
|
wind direction (degrees) |
3 |
175 |
|
|
source file for data used (for CO2) |
12 |
SIPICK1998a.DAT |
|
Use of the 3 data flags depends on the nature of the sampling and analysis used to obtain the measurement. Please consult the scientists cited in the appropriate “readme.txt” file for details.
Data formats for continuous measurements and other more extensive datasets are described in the appropriate “readme.txt” or “readme.doc” files.