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WORLD OCEAN ATLAS 2018
Product Documentation
Ocean Climate Laboratory
NCEI / NESDIS / NOAA
Silver Spring, MD
July 2019
2
For updates on the data, documentation, and additional
information about the WOA18 please refer to:
https://www.nodc.noaa.gov/OC5/woa18
Please cite this document as:
Garcia H.E., T.P. Boyer, O.K. Baranova, R.A. Locarnini, A.V. Mishonov, A. Grodsky, C.R.
Paver, K.W. Weathers, I.V. Smolyar, J.R. Reagan, D. Seidov, M.M. Zweng (2019). World
Ocean Atlas 2018: Product Documentation. A. Mishonov, Technical Editor.
This document is available on line at:
https://data.nodc.noaa.gov/woa/WOA18/DOC/woa18documentation.pdf
NOAA National Centers for
Environmental Information
Additional copies of this publication, as well as information
about NCEI data holdings and services, are available upon
request directly from NCEI.
NOAA/NESDIS
National Centers for Environmental Information
SSMC 3, 4th floor
1315 East-West Highway
Silver Spring, MD 20910-3282
Telephone: (301) 713-3277
E-mail: NCEI.Info@noaa.gov
WEB: https://www.ncei.noaa.gov/
3
Table of Contents
To Sydney (Syd) Levitus ................................................................................................................ 4
Acknowledgments........................................................................................................................... 5
World Ocean Atlas 2018 (WOA18) Product Documentation ........................................................ 6
• Available grid resolution...................................................................................................... 7
• Available time spans and time periods ................................................................................ 7
• Available fields .................................................................................................................... 8
• Available oceanographic variables. ..................................................................................... 9
• Data formats ....................................................................................................................... 11
• File naming convention...................................................................................................... 12
• Utilities ............................................................................................................................... 12
A. Installing gzip for the first time ...................................................................................... 12
B. Decompressing data from WOA ..................................................................................... 13
Appendix 1. Basins defined for objective analysis and the shallowest standard depth level for
which each basin is defined. ..................................................................................................... 14
Appendix 2. Sample from csv file format ................................................................................. 15
Appendix 3. Sample from netCDF file format ......................................................................... 17
List of Tables
Table 1. Time Spans for World Ocean Atlas 2018 ......................................................................... 7
Table 2. Available objectively analyzed and statistical fields ........................................................ 8
Table 3. Depths associated with each standard level number. The maximum depth of the WOA18
is 5500 m (Table 4). ...................................................................................................................... 10
Table 4. Depth ranges and standard depth levels numbers for annual, seasonal, and monthly
statistics of each available oceanographic variable. ..................................................................... 11
4
To Sydney (Syd) Levitus
Syd exemplifies the craft of
careful, systematic inquiry of the large-
scale distributions and low-frequency
variability from seasonal-to-decadal
time scales of ocean properties. He was
one of the first to recognize the
importance and benefits of creating
objectively analyzed climatological
fields of measured ocean variables
including temperature, salinity,
oxygen, nutrients, and derived fields
such as mixed layer depth. Upon
publishing Climatological Atlas of the
World Ocean in 1982, he distributed
this work without restriction, an act not common at the time. This seminal atlas moved the
oceanographic diagnostic research from using hand-drawn maps to using objectively analyzed
fields of ocean variables.
With his NODC Ocean Climate Laboratory (OCL) colleagues, and unprecedented
cooperation from the U.S. and international ocean scientific and data management communities,
he created the World Ocean Database (WOD); the world’s largest collection of ocean profile data
that are available internationally without restriction. The World Ocean Atlas (WOA) series
represents the gridded objective analyses of the WOD and these fields have also been made
available without restriction.
The WOD and WOA series are used so frequently that they have become known
generically as the “Levitus Climatology”. These databases and products enable systematic studies
of ocean variability in its climatological context that were not previously possible. His foresight in
creating WOD and WOA has been demonstrated by their widespread use over the years. Syd has
made major contributions to the scientific and ocean data management communities. He has also
increased public understanding of the role of the oceans in climate. He retired in 2013 after 39
years of distinguished civil service. He distilled the notion of the synergy between rigorous data
management and science; there are no shortcuts.
All of us at the Ocean Climate Laboratory would like to dedicate this atlas to Syd, his
legacy, vision, and mentorship.
The OCL team members
5
Acknowledgments
This work was made possible by a grant from the NOAA Climate and Global Change Program,
which enabled the establishment of a research group at the National Oceanographic Data Center
(now the National Centers for Environmental Information – NCEI). The purpose of this group is
to prepare research quality oceanographic databases, as well as to compute objective analyses of,
and diagnostic studies based on, these databases. Support is now from base funds and from the
NOAA Climate Program Office.
The data on which this atlas is based are in World Ocean Database 2018 and are distributed on-
line by NCEI. Many data were acquired as a result of the IOC/IODE Global Oceanographic Data
Archaeology and Rescue (GODAR) project, and the IOC/IODE World Ocean Database project
(WOD).
The WOD is a composite of publicly available ocean profile data, both historical and recent. We
acknowledge the scientists, technicians, and programmers who have collected and processed data,
those individuals who have submitted data to national and regional data centers as well as the
managers and staff at the various data centers. We are working on a more substantive and
formalized way to acknowledge all those who have collected and contributed to oceanographic
measurements, which were used to calculate the fields in the WOA. Until we have such a system
in place, we direct the reader’s attention to lists of primary investigators, institutions, and projects,
which contributed data (codes can be used to locate data in the World Ocean Database). We also
thank our colleagues at the NCEI. Their efforts have made this and similar works possible.
We dedicate this work to Carla Coleman who always contributed
with a smile and was taken from us too soon.
6
World Ocean Atlas 2018 (WOA18) Product Documentation
Summary: This document describes the World Ocean Atlas 2018 (WOA18) statistical and
objectively analyzed field data files. This description includes the types of statistical fields
available, the oceanographic variables analyzed, and at which standard depth levels, time spans,
time periods and grid resolutions they were analyzed. This description also includes the naming
convention for the files, as well as the structure and format for the files. For a description of the
data used, and the procedures for calculating WOA statistical fields, see
https://www.nodc.noaa.gov/OC5/woa18/pubwoa18.html
The World Ocean Atlas 2018 (WOA18) release – July 2019 updates previous versions of
the World Ocean Atlas to include approximately 3 million new oceanographic casts added to the
World Ocean Database (WOD) since previous release as well as renewed and updated quality
control. The WOA18 temperature and salinity fields are being released as preliminary in order to
take advantage of community-wide quality assurance and comments. After release of the previous
version of the WOA in 2013, we received a number of communications pointing out suspect
features in the released fields. We investigated these features, provided explanations, and when
necessary made new quality flagging decisions, resulting in a version 2 of WOA13. We would
ask that if users of the atlas find any suspect features in WOA18, they please contact us
(OCLhelp@noaa.gov) with an explanation of the problem. We will investigate and make any
necessary quality decisions before preparing a final WOA18 version.
Grey-shaded cells in Table 4 indicate variables which have not yet been released. The
following publications are released concurrently with the final version of WOA18. These
publications are available at the WOA18 web: https://www.nodc.noaa.gov/OC5/woa18/
Locarnini, R.A., A.V. Mishonov, O.K. Baranova, T.P. Boyer, M.M. Zweng, H.E. Garcia, J.R.
Reagan, D. Seidov, K.W. Weathers, C. R.Paver, I.V. Smolyar (2019). World Ocean Atlas
2018, Volume 1: Temperature. A. Mishonov Technical Editor, NOAA Atlas NESDIS 81.
Zweng, M.M, J.R. Reagan, D. Seidov, T.P. Boyer, R.A. Locarnini, H.E. Garcia, A.V. Mishonov,
O.K. Baranova, K.W. Weathers, C.R. Paver, I.V. Smolyar (2019). World Ocean Atlas 2018,
Volume 2: Salinity. A. Mishonov Technical Editor, NOAA Atlas NESDIS 82.
Garcia H.E., K.W. Weathers, C.R. Paver, I.V. Smolyar, T.P. Boyer, R.A. Locarnini, M.M. Zweng,
A.V. Mishonov, O.K. Baranova, J.R. Reagan (2019a). World Ocean Atlas 2018, Volume 3:
Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation. A. Mishonov
Technical Editor, NOAA Atlas NESDIS 83.
Garcia H.E., K.W. Weathers, C.R. Paver, I.V. Smolyar, T.P. Boyer, R.A. Locarnini, M.M. Zweng,
A.V. Mishonov, O.K. Baranova, J.R. Reagan (2019b). World Ocean Atlas 2018, Volume 4:
Dissolved Inorganic Nutrients (phosphate, nitrate, silicate). A. Mishonov Technical Editor,
NOAA Atlas NESDIS 84.
7
Locarnini, R.A., M.M. Zweng, A.V. Mishonov, O.K. Baranova, J.R. Reagan, D. Seidov, T.P.
Boyer, H.E. Garcia, C.R. Paver, K.W. Weathers, I.V. Smolyar (2019b). World Ocean Atlas
2018, Volume 5: In situ Density. A. Mishonov Technical Editor, NOAA Atlas NESDIS 85.
Reagan, J.R., M.M. Zweng, R.A. Locarnini, D. Seidov, A.V. Mishonov, O.K. Baranova, T.P.
Boyer, H.E. Garcia, K.W. Weathers, C.R. Paver, I.V. Smolyar (2019). World Ocean Atlas
2018, Volume 6: Ocean Conductivity. A. Mishonov Technical Editor, NOAA Atlas NESDIS
86.
Boyer, T.P., O.K. Baranova, C. Coleman, H.E. Garcia, A. Grodsky, R.A. Locarnini, A.V.
Mishonov, C.R. Paver, J.R. Reagan, D. Seidov, I.V. Smolyar, K.W. Weathers, M.M. Zweng
(2019). World Ocean Database 2018. A. Mishonov, Technical Editor, NOAA Atlas NESDIS
87.
• Available grid resolution
The World Ocean Atlas 2018 has objectively analyzed climatological mean fields on both a
quarter- and on a one-degree longitude/latitude grids. Statistical fields used in quality control (but
not objectively analyzed climatological means) are available on a five-degree longitude/latitude
grid.
• Available time spans and time periods
Time span refers to the years represented in the climatological mean and statistical fields. Time
period refers to the divisions of a calendar year. The time periods are annual, seasonal (by three-
month periods; Winter = January, February, and March; Spring, Summer, and Fall are the
sequentially following three-month periods), and monthly. Time spans are mostly decadal (10
year) spans, but also include ‘all’, denoting all data used regardless of year, and ‘decav’, an average
of all available (year specific) time spans. An objective analysis for a specific time period is
considered to be representative of that time period for the given time span. Table 1 lists all time
spans that are part of WOA18.
Table 1. Time Spans for World Ocean Atlas 2018
Time Span Abbreviation Comment
1955 – 1964
5564
First decade with sufficient data for climatological mean fields
1965 – 1974
6574
1975 – 1984
7584
1985 – 1994
8594
1995 – 2004
95A4
2005 – 2017
A5B7
Global coverage of Argo floats from 2005
1981 – 2010
decav
Climate Normal
All available
years
all
8
• Available fields
Table 2 presents the list of statistical fields and the grid resolutions at which the fields are
available. Quarter-degree fields represent the world as 1440x720 quarter-degree longitude /
latitude boxes. One-degree fields represent the world as 360x180 one-degree longitude / latitude
boxes. Five-degree fields divide the world into 72x36 five-degree longitude / latitude boxes. Five-
degree statistical fields are the fields used for standard deviation window checks to filter the data;
data that pass these statistical checks are then used to calculate the quarter-degree and one-degree
climatology fields.
Table 2. Available objectively analyzed and statistical fields
Field Name
Quarter-
degree field
calculated
One-degree
field
calculated
Five-degree
field
calculated
Field Type
Code (for
file names)
Objectively analyzed climatology √ √ an
Statistical mean √ √ √ mn
Number of observations √ √ √ dd
Seasonal or monthly climatology
minus annual climatology √ √ ma
Standard deviation from statistical
mean √ √ √ sd
Standard error of the statistical
mean √ √ √ se
Statistical mean minus objectively
analyzed climatology √ √ oa
Number of mean values within
radius of influence √ √ gp
Short description of the statistical fields in WOA18
• Objectively analyzed climatologies are the resulting mean fields for an oceanographic
variable at standard depth levels for the World Ocean.
• The statistical mean is the average of all depth interpolated data values that pass quality
control checks at each standard depth level for each variable in each quarter-degree, one-
degree, or five-degree square which contain at least one measurement for the given
oceanographic variable.
• The number of observations of each variable in each quarter-degree, one-degree, or five-
degree square of the World Ocean at each standard depth level that pass quality control
checks.
• The standard deviation about the statistical mean of each variable in each quarter-degree,
9
one-degree, or five-degree square at each standard depth level that pass quality control
checks.
• The standard error of the mean of each variable in each quarter-degree, one-degree, or
five-degree square at each standard depth level that pass quality control checks.
• The seasonal or monthly climatology minus the annual climatology at each quarter-
degree or one-degree square at each standard depth.
• The statistical mean minus the climatological mean at each quarter-degree or one-degree
square at each standard depth. This value is used as an estimate of interpolation and
smoothing error.
• The number of one-degree squares within the smallest radius of influence around each
quarter-degree or one-degree square that contain a statistical mean value.
In addition to the statistical fields found in
https://www.nodc.noaa.gov/OC5/WOA18/woadata18.html, there are two types of mask files
(ending in suffix .msk). These files contain information used to calculate the statistical fields.
• The landsea_XX.msk contains the standard depth level number at which the bottom of the
ocean is first encountered at each quarter-degree or one-degree square for the entire world.
Land will have a value of 1, corresponding to the surface. Values of standard depth levels
are listed in Table 3.
• The basin_XX.msk contains the basin code number defined for each grid square at each
standard depth from the surface to 5500m. Each basin is identified by a code number that
ranges from 1 to 58. The basin code number in a given quarter-degree and one-degree
square may change with increased depth level. Appendix 1 lists the geographic basin
names, the code number associated with each basin, and the standard depth level at which
the given basin is first encountered.
XX in the above mask names is either 01 (one-degree) or 04 (quarter-degree), depending on the
resolution used to generate the land-sea and basin masks. These mask files are found at
https://data.nodc.noaa.gov/woa/WOA18/MASKS/.
• Available oceanographic variables.
The statistical fields were calculated for six oceanographic variables: temperature, salinity,
dissolved oxygen, nitrate, phosphate, and silicate. Due to the irregularity in data in spatial and
temporal distribution at various depths for different variables, not all variables were analyzed at
all depths for all averaging periods (annual, individual seasons and months). Table 4 lists the
depth limits for each variable for each averaging period.
Temperature and Salinity fields are available on one-degree and quarter-degree grids as
follow:
• One-degree annual, seasonal, and monthly fields are available for 5564, 6574, 7584,
8594, 95A4, A5B7, and ‘decav’ time spans;
• Quarter-degree annual and seasonal fields are available for 5564, 6574, 7584, 8594,
95A4, A5B7, and ‘decav’ time spans;
• Quarter-degree monthly fields are ONLY available for A5B7 and ‘decav’ time spans.
10
One-degree and quarter-degree grids Temperature and Salinity fields are NOT available for
the ‘all’ time span.
Oxygen, Nitrate, Phosphate, and Silicate fields are available ONLY for one-degree grid and
for the ‘all’ time span.
Five-degree grid statistics are available only for ‘all’ time span.
Table 3. Depths associated with each standard level number. The maximum depth of the
WOA18 is 5500 m (Table 4).
Depth
(m)
Level
Depth
(m)
Level
Depth
(m)
Level
Depth
(m)
Level
0
1
475
36
2300
70
5700
104
5
2
500
37
2400
71
5800
105
10
3
550
38
2500
72
5900
106
15
4
600
39
2600
73
6000
107
20
5
650
40
2700
74
6100
108
25
6
700
41
2800
75
6200
109
30
7
750
42
2900
76
6300
110
35
8
800
43
3000
77
6400
111
40
9
850
44
3100
78
6500
112
45
10
900
45
3200
79
6600
113
50
11
950
46
3300
80
6700
114
55
12
1000
47
3400
81
6800
115
60
13
1050
48
3500
82
6900
116
65
14
1100
49
3600
83
7000
117
70
15
1150
50
3700
84
7100
118
75
16
1200
51
3800
85
7200
119
80
17
1250
52
3900
86
7300
120
85
18
1300
53
4000
87
7400
121
90
19
1350
54
4100
88
7500
122
95
20
1400
55
4200
89
7600
123
100
21
1450
56
4300
90
7700
124
125
22
1500
57
4400
91
7800
125
150
23
1550
58
4500
92
7900
126
175
24
1600
59
4600
93
8000
127
200
25
1650
60
4700
94
8100
128
225
26
1700
61
4800
95
8200
129
250
27
1750
62
4900
96
8300
130
275
28
1800
63
5000
97
8400
131
300
29
1850
64
5100
98
8500
132
325
30
1900
65
5200
99
8600
133
350
31
1950
66
5300
100
8700
134
375
32
2000
67
5400
101
8800
135
400
33
2100
68
5500
102
8900
136
425
34
2200
69
5600
103
9000
137
450
35
11
Table 4. Depth ranges and standard depth levels numbers for annual, seasonal, and
monthly statistics of each available oceanographic variable.
Please note that the WOA18 will be released incrementally. Grey-shaded cells in Table 4
indicate variables, which have not yet been released.
One-letter codes are first letter of file names for given variable.
Oceanographic
Variable
(one-letter code)
Depths for
Annual
Climatology
Depths for
Seasonal
Climatology
Depths for
Monthly
Climatology
Temperature (t) 0-5500 meters
(102 levels) 0-5500 meters
(102 levels) 0-1500 meters
(57 levels)
Salinity (s) 0-5500 meters
(102 levels) 0-5500 meters
(102 levels) 0-1500 meters
(57 levels)
Oxygen (o) 0-5500 meters
(102 levels 0-1500 meters
(57 levels) 0-1500 meters
(57 levels)
Nitrate (n) 0-5500 meters
(102 levels) 0-800 meters
(43 levels) 0-800 meters
(43 levels)
Phosphate (p) 0-5500 meters
(102 levels) 0-800 meters
(43 levels) 0-800 meters
(43 levels)
Silicate (i) 0-5500 meters
(102 levels) 0-800 meters
(43 levels) 0-800 meters
(43 levels)
• Data formats
WOA18 data files are available in four formats:
• Climate and Forecast (CF) compliant Network Common Data Format (NetCDF) ,
• Comma-separated value (csv) format,
• ArcGIS-compatible shapefiles,
• Compact grid format (a legacy WOA ASCII format)
Appendix 2 gives an example of the csv format and Appendix 3 gives an example of the structure
of the netCDF file. The legacy ASCII format files are provided for applications that have been set
up to read this format in previous WOA releases. Usage of this format is not encouraged, as it
does not explicitly give depth, possibly resulting in confusion when reading WOA18 files in
software set up for previous releases of World Ocean Atlas, or vice-versa.
For information regarding to the legacy WOA ASCII format, please see
https://data.nodc.noaa.gov/woa/WOA18/DOC/woa18documentation.pdf. Each csv file contains
all depths for a single statistical field; please note that this differs from the csv files released for
WOA18.
12
• File naming convention
All files, regardless of format, are follows the same naming convention:
woa18_[DECA]_[v][tp][ft][gr].[form_end]
Where:
[DECA] represents decade, the time span (years) represented by the objectively analyzed
means and other statistical fields as listed in Table 1:
[v] represents the oceanographic variable using one-letter code as listed in Table 4;
[tp] represents the averaging period, two digit code as follows:
00 – annual statistics, all data used;
01 to 12 – monthly statistics (starting with 01 – January, to 12 – December);
13 to 16 – seasonal statistics:
Season 13 – North Hemisphere winter (January - March);
Season 14 – North Hemisphere spring (April - June);
Season 15 – North Hemisphere summer (July - September);
Season 16 – North Hemisphere autumn (October - December);
[ft] represents field type, describing the calculated statistic represented in the file, as listed
in Table 2
[gr] represents the grid size, two digit code as follows:
04 – quarter-degree grid resolution
01 – one-degree grid resolution
5d – five-degree grid resolution
[form_end] format suffix (filename extension), dependent on format as follows:
csv – comma-separated value format
nc – netCDF format
dbf, shp, shx – shapefiles (when downloaded will be in a .tar file together)
dat – compact grid data format (legacy WOA ASCII format)
Example: woa18_95A4_s02an01.nc is a file containing World Ocean Atlas 2018, February
objectively analyzed salinity on one-degree grid resolution for the years 1995-2004 in netCDF
format.
• Utilities
Folder utils contains decompression freeware: gzip124.exe – self-extracting DOS executable, and
gzip124.tar – a compressed file containing source code for UNIX users.
A. Installing gzip for the first time
DOS Users: The file gzip124.exe is a self-extracting DOS executable.
Copy gzip124.exe to your hard drive,
Run gzip124.exe and use the file gzip.exe to uncompress data as described in Section B.
13
UNIX Users:
Copy gzip124.tar to your UNIX system
Run the following command: tar -xvf gzip124.tar
This command will create a directory named gzip-1.2.4 that includes the gzip source code and
documentation about copyrights, compression methods and how to compile and install the gzip
code. Read through the README file and when ready to build the gzip executable, follow
instructions in the INSTALL file.
B. Decompressing data from WOA
To decompress the WOA files, it is recommended to first copy the data files to a hard disk. Use
gzip to decompress selected files or a directory and all subdirectories with one command. The
gzip utility has a limited help menu accessible with the -h option (e.g. gzip -h); additional
information may be found at www.gzip.org.
To decompress a single file:
gzip -nd <filename>
To decompress the contents of a directory and all of its subdirectories:
gzip -ndr <directoryname>
If an older version of gzip is used, the -n option is required in order to preserve the correct file
names.
14
Appendix 1. Basins defined for objective analysis and the shallowest
standard depth level for which each basin is defined.
# BASIN1
STANDARD
DEPTH
LEVEL
# BASIN1
STANDARD
DEPTH
LEVEL
1 Atlantic Ocean 1*
30
North American Basin
82
2 Pacific Ocean 1*
31
West European Basin
82
3 Indian Ocean 1* 32 Southeast Indian Basin 82
4 Mediterranean Sea 1* 33 Coral Sea 82
5 Baltic Sea 1 34 East Indian Basin 82
6 Black Sea 1 35 Central Indian Basin 82
7 Red Sea 1 36 Southwest Atlantic Basin 82
8 Persian Gulf 1 37 Southeast Atlantic Basin 82
9 Hudson Bay 1 38 Southeast Pacific Basin 82
10 Southern Ocean 1* 39 Guatemala Basin 82
11 Arctic Ocean 1 40 East Caroline Basin 87
12 Sea of Japan 1 41 Marianas Basin 87
13 Kara Sea 22 42 Philippine Sea 87
14 Sulu Sea 25 43 Arabian Sea 87
15 Baffin Bay 37 44 Chile Basin 87
16 East Mediterranean 41 45 Somali Basin 87
17 West Mediterranean 47 46 Mascarene Basin 87
18 Sea of Okhotsk 47 47 Crozet Basin 87
19 Banda Sea 55 48 Guinea Basin 87
20 Caribbean Sea 55
49
Brazil Basin
92
21 Andaman Basin 62
50
Argentine Basin
92
22 North Caribbean 67
51
Tasman Sea
87
23 Gulf of Mexico 67
52
Atlantic Indian Basin
92
24 Beaufort Sea 77 53 Caspian Sea 1
25 South China Sea 77 54 Sulu Sea II 37
26 Barents Sea 77 55 Venezuela Basin 37
27 Celebes Sea 62 56 Bay of Bengal 1*
28 Aleutian Basin 77 57 Java Sea 16
29 Fiji Basin 82 58 East Indian Atlantic Basin 97
1Basins marked with a “*” can interact with adjacent basins in the objective analysis.
15
Appendix 2. Sample from csv file format
File=woa18_5564_t00an01.csv (showing only the first 30 lines of the file)
#WOA18 one-degreeANNUAL temperature Climatological mean
#COMMA SEPARATED LATITUDE, LONGITUDE, AND VALUES AT DEPTHS
(M):0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100,125,150,175,200,225,250,275,300,3
25,350,375,400,425,450,475,500,550,600,650,700,750,800,850,900,950,1000,1050,1100,1150,1200,125
0,1300,1350,1400,1450,1500,1550,1600,1650,1700,1750,1800,1850,1900,1950,2000,2100,2200,2300,2
400,2500,2600,2700,2800,2900,3000,3100,3200,3300,3400,3500,3600,3700,3800,3900,4000,4100,4200
,4300,4400,4500,4600,4700,4800,4900,5000,5100,5200,5300,5400,5500
-77.500,-178.500,-1.202,-1.247,-1.291,-1.303,-1.304,-1.308,-1.360,-1.405,-1.452,-1.504,-1.537,-1.569,-
1.599,-1.613,-1.630,-1.629,-1.638,-1.634,-1.642,-1.644,-1.646,-1.648,-1.673,-1.725,-1.735,-1.778,-1.842,-
1.851,-1.912,-1.991,-2.035,-2.056,-2.063,-2.098,-2.087,-2.082,-2.087,-2.005,-1.960
-77.500,-177.500,-1.215,-1.260,-1.315,-1.327,-1.322,-1.314,-1.349,-1.388,-1.433,-1.487,-1.521,-1.552,-
1.588,-1.607,-1.627,-1.630,-1.644,-1.644,-1.653,-1.655,-1.657,-1.660,-1.685,-1.742,-1.750,-1.797,-1.843,-
1.863,-1.915,-1.990,-2.034,-2.054,-2.062,-2.097,-2.086,-2.080,-2.086,-2.011,-1.969
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1.605,-1.622,-1.639,-1.641,-1.654,-1.654,-1.663,-1.666,-1.667,-1.675,-1.702,-1.755,-1.765,-1.817,-1.877,-
1.873,-1.913,-1.984,-2.028,-2.053,-2.058,-2.093,-2.083,-2.078,-2.084,-2.015,-1.978,-0.895
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1.627,-1.640,-1.657,-1.653,-1.666,-1.666,-1.673,-1.679,-1.679,-1.690,-1.710,-1.767,-1.781,-1.837,-1.882,-
1.886,-1.915,-1.978,-2.018,-2.041,-2.052,-2.084,-2.073,-2.067,-2.081,-2.009,-1.986
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1.891,-1.913,-1.973,-2.009,-2.036,-2.044,-2.078,-2.067,-2.063,-2.074,-2.008,-1.997
-77.500,-173.500,-1.417,-1.429,-1.452,-1.445,-1.437,-1.409,-1.424,-1.453,-1.490,-1.538,-1.578,-1.600,-
1.636,-1.658,-1.675,-1.676,-1.687,-1.692,-1.698,-1.703,-1.711,-1.723,-1.737,-1.784,-1.792,-1.862,-1.894,-
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-77.500,-172.500,-1.405,-1.425,-1.461,-1.465,-1.474,-1.468,-1.477,-1.501,-1.532,-1.582,-1.615,-1.637,-
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1.898,-1.908,-1.962,-1.989,-2.001,-2.020,-2.052,-2.044,-2.053,-2.062,-1.999,-2.016
-77.500,-171.500,-1.421,-1.401,-1.435,-1.426,-1.429,-1.430,-1.441,-1.469,-1.505,-1.551,-1.589,-1.612,-
1.641,-1.662,-1.679,-1.680,-1.696,-1.707,-1.723,-1.737,-1.757,-1.760,-1.793,-1.852,-1.843,-1.911,-1.925,-
1.909,-1.923,-1.974,-1.992,-1.991,-2.008,-2.032,-2.026,-2.046,-2.048,-1.994,-2.017
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1.643,-1.654,-1.666,-1.669,-1.683,-1.698,-1.713,-1.730,-1.760,-1.780,-1.812,-1.862,-1.854,-1.920,-1.922,-
1.896,-1.910,-1.956,-1.967,-1.949,-1.961,-1.964,-1.969,-2.012,-2.035,-1.976,-2.013
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-77.500,-167.500,-1.469,-1.499,-1.567,-1.570,-1.588,-1.599,-1.581,-1.572,-1.584,-1.604,-1.621,-1.632,-
1.648,-1.660,-1.674,-1.674,-1.688,-1.702,-1.719,-1.735,-1.757,-1.790,-1.822,-1.856,-1.857,-1.922,-1.913,-
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1.627,-1.647,-1.668,-1.670,-1.684,-1.700,-1.717,-1.733,-1.755,-1.796,-1.824,-1.857,-1.856,-1.924,-1.936,-
1.860,-1.857,-1.879,-1.888,-1.874,-1.861
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1.844,-1.837,-1.846,-1.847,-1.821,-1.812
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16
1.612,-1.628,-1.647,-1.651,-1.665,-1.679,-1.692,-1.706,-1.728,-1.753,-1.804,-1.854,-1.833,-1.869,-1.892,-
1.826,-1.810,-1.742,-1.702,-1.670,-1.629,-1.656,-1.706,-1.782,-1.825
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1.623,-1.639,-1.658,-1.663,-1.678,-1.693,-1.709,-1.727,-1.763,-1.795,-1.837,-1.856,-1.836,-1.884,-1.917,-
1.848,-1.802,-1.758,-1.731,-1.705,-1.676,-1.686,-1.697,-1.734,-1.744,-1.762,-1.891
-77.500,-162.500,-1.485,-1.553,-1.630,-1.628,-1.637,-1.647,-1.668,-1.682,-1.670,-1.617,-1.599,-1.596,-
1.610,-1.623,-1.567,-1.553,-1.537,-1.556,-1.624,-1.676,-1.726,-1.768,-1.805,-1.831,-1.819,-1.858,-1.851,-
1.798,-1.742,-1.683,-1.635,-1.628,-1.611,-1.623,-1.649,-1.687,-1.687,-1.735,-1.812,-
1.825,0.933,1.108,1.099
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1.616,-1.626,-1.641,-1.640,-1.619,-1.605,-1.612,-1.632,-1.656,-1.724,-1.772,-1.812,-1.788,-1.811,-1.832,-
1.755,-1.711,-1.681,-1.640,-1.638,-1.627,-1.619,-1.622,-1.649,-1.659,-1.722,-1.849,-1.907
-77.500,-160.500,-1.491,-1.538,-1.617,-1.639,-1.647,-1.649,-1.672,-1.684,-1.701,-1.719,-1.664,-1.637,-
1.638,-1.635,-1.596,-1.585,-1.549,-1.554,-1.586,-1.641,-1.682,-1.732,-1.762,-1.794,-1.779,-1.798,-1.803,-
1.727,-1.674,-1.631,-1.577,-1.601,-1.592,-1.577,-1.574,-1.608,-1.618,-1.713,-1.778,-
1.878,0.889,1.086,1.092
-77.500,-159.500,-1.502,-1.550,-1.624,-1.645,-1.648,-1.649,-1.619,-1.608,-1.610,-1.603,-1.620,-1.606,-
1.608,-1.610,-1.621,-1.622,-1.632,-1.648,-1.655,-1.680,-1.688,-1.729,-1.750,-1.793,-1.786,-1.805,-1.808,-
1.699,-1.635,-1.576,-1.517
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1.585,-1.592,-1.569,-1.602,-1.649,-1.700,-1.777,-1.851,-1.896,-1.902,-1.908,-1.904,-1.897,-1.857,-1.915,-
1.942,-1.904,-1.841,-1.808
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1.645,-1.718,-1.752,-1.779,-1.804,-1.824,-1.856,-1.886,-1.914,-1.922,-1.942,-1.940,-1.935,-1.897,-1.952,-
1.948,-1.860,-1.772,-1.717,-1.679,-1.656,-1.597
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1.466,-1.508,-1.531,-1.530,-1.581,-1.645,-1.738,-1.834,-1.894,-1.915,-1.939,-1.935,-1.941,-1.895,-1.966,-
1.951,-1.882,-1.821,-1.772,-1.706,-1.637,-1.547,-1.518,-1.520,-1.532,-1.454
-77.500,-41.500,-1.671,-1.591,-1.695,-1.692,-1.713,-1.733,-1.752,-1.710,-1.680,-1.665,-1.632,-1.626,-
1.634,-1.647,-1.645,-1.642,-1.637,-1.677,-1.736,-1.815,-1.871,-1.900,-1.925,-1.901,-1.902,-1.839,-1.939,-
1.931,-1.861,-1.808,-1.762,-1.688,-1.620,-1.516,-1.498,-1.506,-1.553,-1.408,-1.744,-1.823
-77.500,-40.500,-1.581,-1.535,-1.657,-1.679,-1.712,-1.736,-1.756,-1.767,-1.774,-1.771,-1.748,-1.744,-
1.754,-1.767,-1.763,-1.759,-1.759,-1.790,-1.817,-1.841,-1.869,-1.880,-1.905,-1.903,-1.909,-1.767,-1.896,-
1.888,-1.826,-1.791,-1.743,-1.667,-1.593,-1.480,-1.452,-1.467,-1.485,-1.373,-1.702,-1.792,-1.879,-1.940,-
1.959,-2.009
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1.663,-1.680,-1.687,-1.645,-1.607,-1.687,-1.760,-1.822,-1.863,-1.881,-1.910,-1.907,-1.906,-1.741,-1.891,-
1.879,-1.835,-1.791,-1.733,-1.649,-1.572,-1.428,-1.402,-1.418,-1.432,-1.354,-1.671,-1.775,-1.833,-1.919,-
1.941,-1.996,-2.012,-2.017,-2.051
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1.675,-1.673,-1.694,-1.739,-1.776,-1.835,-1.876,-1.887,-1.894,-1.910,-1.930,-1.924,-1.941,-1.764,-1.906,-
1.890,-1.865,-1.797,-1.735,-1.653,-1.567,-1.423,-1.392,-1.403,-1.415,-1.359,-1.663,-1.762,-1.811,-1.888,-
1.908,-1.985,-2.002,-2.006,-2.040,-1.973,-2.022,-1.200
-77.500,-37.500,-1.442,-1.475,-1.515,-1.533,-1.578,-1.585,-1.602,-1.616,-1.626,-1.622,-1.626,-1.644,-
1.664,-1.668,-1.687,-1.727,-1.761,-1.820,-1.858,-1.882,-1.898,-1.910,-1.933,-1.934,-1.954,-1.789,-1.899,-
1.885,-1.870,-1.794,-1.739,-1.660,-1.575,-1.451,-1.422,-1.423,-1.432,-1.379,-1.662,-1.757,-1.820,-1.895,-
1.928,-1.978,-1.993,-1.995,-2.029,-1.961,-2.005,-1.310
17
Appendix 3. Sample from netCDF file format
netcdf woa18_5564_t00_01 {
dimensions:
nbounds = 2 ;
lat = 180 ;
lon = 360 ;
depth = 102 ;
time = 1 ;
variables:
int crs ;
crs:grid_mapping_name = "latitude_longitude" ;
crs:epsg_code = "EPSG:4326" ;
crs:longitude_of_prime_meridian = 0.f ;
crs:semi_major_axis = 6378137.f ;
crs:inverse_flattening = 298.2572f ;
float lat(lat) ;
lat:standard_name = "latitude" ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
lat:axis = "Y" ;
lat:bounds = "lat_bnds" ;
float lat_bnds(lat, nbounds) ;
lat_bnds:comment = "latitude bounds" ;
float lon(lon) ;
lon:standard_name = "longitude" ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
lon:axis = "X" ;
lon:bounds = "lon_bnds" ;
float lon_bnds(lon, nbounds) ;
lon_bnds:comment = "longitude bounds" ;
float depth(depth) ;
depth:standard_name = "depth" ;
depth:bounds = "depth_bnds" ;
depth:positive = "down" ;
depth:units = "meters" ;
depth:axis = "Z" ;
float depth_bnds(depth, nbounds) ;
depth_bnds:comment = "depth bounds" ;
float time(time) ;
time:standard_name = "time" ;
time:long_name = "time" ;
time:units = "months since 1955-01-01 00:00:00" ;
time:axis = "T" ;
time:climatology = "climatology_bounds" ;
float climatology_bounds(time, nbounds) ;
climatology_bounds:comment = "This variable defines the bounds of the climatological time
period for each time" ;
float t_an(time, depth, lat, lon) ;
t_an:standard_name = "sea_water_temperature" ;
t_an:long_name = "Objectively analyzed mean fields for sea_water_temperature at standard
depth levels." ;
t_an:coordinates = "time lat lon depth" ;
18
t_an:cell_methods = "area: mean depth: mean time: mean within years time: mean over years"
;
t_an:grid_mapping = "crs" ;
t_an:units = "degrees_celsius" ;
t_an:_FillValue = 9.96921e+36f ;
float t_mn(time, depth, lat, lon) ;
t_mn:standard_name = "sea_water_temperature" ;
t_mn:long_name = "Average of all unflagged interpolated values at each standard depth level
for sea_water_temperature in each grid-square which contain at least one measurement." ;
t_mn:coordinates = "time lat lon depth" ;
t_mn:cell_methods = "area: mean depth: mean time: mean within years time: mean over years"
;
t_mn:grid_mapping = "crs" ;
t_mn:units = "degrees_celsius" ;
t_mn:_FillValue = 9.96921e+36f ;
int t_dd(time, depth, lat, lon) ;
t_dd:standard_name = "sea_water_temperature number_of_observations" ;
t_dd:long_name = "The number of observations of sea_water_temperature in each grid-square
at each standard depth level." ;
t_dd:coordinates = "time lat lon depth" ;
t_dd:cell_methods = "area: sum depth: point time: sum" ;
t_dd:grid_mapping = "crs" ;
t_dd:units = "1" ;
t_dd:_FillValue = -32767 ;
float t_sd(time, depth, lat, lon) ;
t_sd:long_name = "The standard deviation about the statistical mean of sea_water_temperature
in each grid-square at each standard depth level." ;
t_sd:coordinates = "time lat lon depth" ;
t_sd:cell_methods = "area: mean depth: mean time: standard_deviation" ;
t_sd:grid_mapping = "crs" ;
t_sd:units = "degrees_celsius" ;
t_sd:_FillValue = 9.96921e+36f ;
float t_se(time, depth, lat, lon) ;
t_se:standard_name = "sea_water_temperature standard_error" ;
t_se:long_name = "The standard error about the statistical mean of sea_water_temperature in
each grid-square at each standard depth level." ;
t_se:coordinates = "time lat lon depth" ;
t_se:cell_methods = "area: mean depth: mean time: mean" ;
t_se:grid_mapping = "crs" ;
t_se:units = "degrees_celsius" ;
t_se:_FillValue = 9.96921e+36f ;
float t_oa(time, depth, lat, lon) ;
t_oa:standard_name = "sea_water_temperature" ;
t_oa:long_name = "statistical mean value minus the objectively analyzed mean value for
sea_water_temperature." ;
t_oa:coordinates = "time lat lon depth" ;
t_oa:cell_methods = "area: mean depth: mean time: mean with years time: mean over years" ;
t_oa:grid_mapping = "crs" ;
t_oa:units = "degrees_celsius" ;
t_oa:_FillValue = 9.96921e+36f ;
int t_gp(time, depth, lat, lon) ;
t_gp:long_name = "The number of grid-squares within the smallest radius of influence around
each grid-square which contain a statistical mean for sea_water_temperature." ;
t_gp:coordinates = "time lat lon depth" ;
19
t_gp:cell_methods = "area: mean depth: mean time: mean within years time: mean over years"
;
t_gp:grid_mapping = "crs" ;
t_gp:units = "1" ;
t_gp:_FillValue = -32767 ;
// global attributes:
:Conventions = "CF-1.6, ACDD-1.3" ;
:title = "World Ocean Atlas 2018 : sea_water_temperature Annual 1955-1964 1.00 degree" ;
:summary = "PRERELEASE Climatological mean temperature for the global ocean from in situ
profile data" ;
:references = "Locarnini, R. A., A. V. Mishonov, O. K. Baranova, T. P. Boyer, M. M. Zweng, H.
E. Garcia, J. R. Reagan, D. Seidov, K. W. Weathers, C. R. Paver, I. V. Smolyar, 2018: World Ocean Atlas
2018, Volume 1: Temperature. A. V. Mishonov, Technical Ed., NOAA Atlas NESDIS ##" ;
:institution = "National Centers for Environmental Information (NCEI)" ;
:comment = "global climatology as part of the World Ocean Atlas project" ;
:id = "woa18_5564_t00_01.nc" ;
:naming_authority = "gov.noaa.ncei" ;
:sea_name = "World-Wide Distribution" ;
:time_coverage_start = "1955-01-01" ;
:time_coverage_end = "1964-12-31" ;
:time_coverage_duration = "P10Y" ;
:time_coverage_resolution = "P01Y" ;
:geospatial_lat_min = -90.f ;
:geospatial_lat_max = 90.f ;
:geospatial_lon_min = -180.f ;
:geospatial_lon_max = 180.f ;
:geospatial_vertical_min = 0.f ;
:geospatial_vertical_max = 5500.f ;
:geospatial_lat_units = "degrees_north" ;
:geospatial_lat_resolution = "1.00 degrees" ;
:geospatial_lon_units = "degrees_east" ;
:geospatial_lon_resolution = "1.00 degrees" ;
:geospatial_vertical_units = "m" ;
:geospatial_vertical_resolution = "SPECIAL" ;
:geospatial_vertical_positive = "down" ;
:creator_name = "Ocean Climate Laboratory" ;
:creator_email = "NCEI.info@noaa.gov" ;
:creator_url = "http://www.ncei.noaa.gov" ;
:creator_type = "group" ;
:creator_institution = "National Centers for Environmental Information" ;
:project = "World Ocean Atlas Project" ;
:processing_level = "processed" ;
:keywords = "Oceans< Ocean Temperature > Water Temperature" ;
:keywords_vocabulary = "ISO 19115" ;
:standard_name_vocabulary = "CF Standard Name Table v49" ;
:contributor_name = "Ocean Climate Laboratory" ;
:contributor_role = "Calculation of climatologies" ;
:cdm_data_type = "Grid" ;
:publisher_name = "National Centers for Environmental Information (NCEI)" ;
:publisher_institution = "National Centers for Environmental Information" ;
:publisher_type = "institution" ;
:publisher_url = "http://www.ncei.noaa.gov/" ;
:publisher_email = "NCEI.info@noaa.gov" ;
20
:nodc_template_version = "NODC_NetCDF_Grid_Template_v2.0" ;
:license = "These data are openly available to the public. Please acknowledge the use of these
data with the text given in the acknowledgment attribute." ;
:metadata_link = "http://www.nodc.noaa.gov/OC5/WOA18/pr_woa18.html" ;
:date_created = "2018-10-06 " ;
:date_modified = "2018-10-06 " ;
}
