About DataSheets
A DataSheet concisely describes a particular scientific dataset in a way that is
useful to people who are interested in learning from or teaching with the data. It
provides educationally relevant metadata to facilitate exploration of the data by
educators and students.
DataSheets highlight the connections between datasets and specific topics in science.
They also explicate how to acquire, interpret, and analyze the data. Information is
presented at a level appropriate for those who don’t have specialized knowledge of the
discipline in which the data are commonly used. The sheets are designed to support
novice or out-of-field data users by providing them with the knowledge necessary to
obtain and use data appropriately for scientific explorations. DataSheets also provide the
meanings for acronyms and other jargon that users are likely to encounter, and include
links to journal articles and educational resources that cite or use the data.
DataSheets have a number of content fields, each with a well-defined structure. The goal
of this structure is to ensure consistency across the range of DataSheets, enabling users to
explore a wide variety of data in an efficient manner. A growing collection of DataSheets
is available at http://serc.carleton.edu/usingdata/browse_sheets.html
Generating DataSheets
This document describes the fields of a DataSheet and shows an example entry for each
one. Please enter information into the template for a single dataset. Complete as
many fields as possible, leaving those that are outside your experience or expertise for
others. Save the completed template document by appending the dataset name to the
current file name.
DataSheet Template
Author(s)
Indicate who prepared the DataSheet and acknowledge experts who were consulted in the
process.
Author(s)
This data sheet was created by Sheri Phillips, Thomas Ryan, Tess Brandon, and John
Antonov of the NOAA National Oceanographic Data Center
DataSheet title
Enter the title for the DataSheet in one of the following formats:
DataSheet Title
Exploring sea level variation using ocean heat content with selected NODC Ocean
Climate Laboratory data.
URLs
List 2 URLs and link text for each:
http://www.nodc.noaa.gov/OC5/
Homepage URL
Link text (generally the
name of the page)
Data access URL
Homepage for National Oceanographic Data Center
http://www.nodc.noaa.gov/OC5/DATA_ANALYSIS/heat_intro.html
National Oceanographic Data Center
Link text (generally
“Access x data” where x
is the data source or type
of data)
Data Description
Give a brief description of the data including how they are presented and their geospatial
and/or temporal extent. Give enough information for users to decide whether they are
interested in exploring the data.
Data
Description
These data files are a collection of global 1° temperature data to 700 meters depth
assembled specifically for use in educational activities with appropriated data viewing
software.
Graphic Representation of Data
When possible, give the URL to a non-copyrighted graphic that shows what the data
product available at the direct link to data site looks like. If no graphic is readily
available, list simple directions for producing a visible picture of the data.
Image URL
Image Caption and
Credit
http://www.nodc.noaa.gov/OC5/DATA_ANALYSIS/yearly.html
*Note: this image may be replaced if Dr. Antonov has a better
image for this exercise.
Use and relevance
This section should discuss the importance of the data, using as little jargon as possible.
It should concisely describe how scientists use these data, including what questions they
helps answer, and how. It should describe why those questions are important to science
as well as their relationship to issues effecting society more broadly.
Use and
relevance
Based on the physical properties and mass of the world ocean as compared to other
components of Earth’s climate system, Rossby (1959) suggested that ocean heat
content may be the dominant component of the variability of the Earth’s heat balance.
Recent work (Levitus et al., 2000, 2001) has confirmed Rossby’s suggestion. Thermal
expansion is a significant component in observed sea level variation determined from
satellite altimetry.
Data type
Describe the nature of the data (e.g. raw, processed, modeled) and how the data are
presented (e.g. graphically, tab-delineated text file).
Data type
Processed gridded heat content data from in situ buoy observations. Depth range
from 0-700 m. Data are presented in both graphical and ASCII text formats.
Thermosteric anomaly is also calculated and is available as a time series and in
graphical fomat.
Accessing data
Explain how to obtain the data. This should include specific guidance on how to find the
data within the site and what exactly will be available when they reach the data. As
necessary (if guidance is not provided by the data access interface) include descriptions
of the fields to address and what the default values will produce.
Accessing data
Users should download (to their hard drive) the prepared set of temperature data files
from the NOAA National Oceanographic Data Center website
(http://www.nodc.noaa.gov/OC5/DATA_ANALYSIS/heat_intro.html) These are
prepared to be imported into the tool “Ocean Data View”
(http://odv.awi.de/en/software/download/)
Acronyms, Initials, and Jargon
List and define acronyms, initials, or discipline-specific jargon users will encounter.
Acronyms,
initials, or
jargon
CTD - an acronym for Conductivity, Temperature, and Depth — is the primary tool for determining
essential physical properties of sea water. It gives scientists a precise and comprehensive charting of the
distribution and variation of water temperature, salinity, and density that helps to understand how the
oceans affect life.
SLA – sea level anomaly – variation of sea surface height, as measured by satellite altimetry, relative to a
10-year average.
Thermosteric sea level – contribution to sea level variation due to heat content and thermal expansion of
seawater.
Thermosteric anomaly – specific volume anomaly (change in sea level) due to the difference between
measured seawater temperature and temperature at 1 atmosphere pressure at 1C.
ODV – ocean data view software, which provides graphical representation of data.
Joule - energy, work, quantity of heat. The International System unit of electrical, mechanical, and thermal
energy. Symbol J (coherent derived unit for entropy, heat capacity = J·K -1
NOAA – National Oceanic and Atmospheric Administration
NODC – National Oceanographic Data Center (NOAA)
OCL – NODC Ocean Climate Laboratory
Subsurface float - A centrally buoyant device, designed to drift at a specific depth below the water's
surface, used to measure water velocity at that depth.
XBT – Expendable Bathythermograph. The XBT has been used by oceanographers for many years to
obtain information on the temperature structure of the ocean to depths of up to 1500 meters. The XBT is a
probe which is dropped from a ship and measures the temperature as it falls through the water. Two very
small wires transmit the temperature data to the ship where it is recorded for later analysis. The probe is
designed to fall at a known rate, so that the depth of the probe can be inferred from the time since it was
launched. By plotting temperature as a function of depth, the scientists can get a picture of the temperature
profile of the water.
Data tools
List and briefly describe data manipulation tools (software) that can be used to work with
the data, including any tools that are integrated into the data access site. When possible,
provide information on obtaining the tools and links to relevant tutorials and tool
documentation.
Data Tools
NOAA/NODC Ocean Climate Laboratory data products may be viewed and
downloaded directly from: http://www.nodc.noaa.gov/OC5/. These pages include
data, data plots and numerous published articles re ocean temperatures, salinity, and
nutrients.
Visualizing data
Suggest ways in which users might manipulate the data to generate visualizations. To
leave the door open for innovative exploration, be explicit that each suggestion is only
‘one way’ to visualize the data (unless the nature of the data is such that only one process
will work).
Visualizing
data
The NODC does not typically provide tools for data visualization and data
manipulation. A suggested visualization tool for the temperature (heat content) data
files is “Ocean Data View” or ODV, downloadable from
http://odv.awi.de/en/software/download/.
Collection methods
This section should provide an overview of the details on how the data are collected
(including information on instrumentation, transmission of data, and post-processing of
data).
Collection
Methods
Ocean water temperatures at depth are collected in situ by various instruments, including
CTDs (conductivity, temperature, and depth instrument), moored instruments, XBTs
(expendable bathythermograph), subsurface floats (RAFOS, ALACE, MARVOR,
PROFILER floats), inverted echo sounders, gliders, and even by using sound waves.
“During the 1990s, when NOAA’s National Oceanographic Data Center expanded its World
Ocean Database, scientists started computing ocean heat content because of its possible
importance in the Earth's heat balance, especially in diagnosing the Earth’s response to the
observed increase in atmospheric greenhouses gases such as carbon dioxide. At that time,
climate and atmospheric scientists hypothesized that increased concentrations of
atmospheric greenhouse gases could lead to an increase in ocean heat content. However,
substantial evidence to verify the hypothesis was not yet available.
The National Oceanographic Data Center's Ocean Climate Laboratory in Silver Spring,
Maryland, set out to test the hypothesis. Researchers at the lab did this by comparing
temperature observations from throughout the world ocean from 1955 to 1998. They
devised mathematical procedures and statistical tests to compare 5.1 million temperature
profiles in the lab's databases. The profiles come from many countries including the United
States, Russia, the United Kingdom, Germany, France, Canada, Australia, and Japan and are
taken from research ships, naval ships, buoys, or merchant ships.
In 2000, the journal Science published “Warming of the World Ocean,” the first paper to
report the results of the NODC ocean warming study. In the article, NODC scientists
concluded that the world ocean had potentially absorbed 20 x 10 22 joules, and warmed 0.06
degrees Fahrenheit. (They revised the energy absorption figure downward to 14.5 X 10 22 in
a 2005 paper entitled “Warming of the World Ocean, 1955-2003,” in the journal
Geophysical Research Letters.). The temperature increase appears to be very small until we
consider that the estimated energy input is equivalent to approximately 10 million
thunderstorms, 100,000,000 Hiroshima-size atomic bombs, or burning approximately 1,000
trillion barrels of oil (more than are known to exist)! Put in other terms, the sudden release
of this energy from the ocean would warm the bottom 10 km (6.2 mi) of the atmosphere
approximately 22 degrees Celsius (40 degrees Fahrenheit).” (NOAA)
(John may want to add to this section re data compiling and processing
methods!!!)
Sources of error
This section should give an overview of the sources of error related to data collection and
processing. It should also discuss limits inherent in any underlying model or
representation and indicate how these limits circumscribe the applicability of the data set
and conclusions drawn from it. When applicable, provide a link to a section of the data
site or a reference to a paper discussing error in the particular data set.
Sources of
Error
Errors may occur within instrument-collected raw data from software “glitches”
causing inaccurate readings or other instrument failure. Improper sensor calibration
on CTDs, etc. In addition, large data sets may be corrected and processed through
various formats, introducing another source of error.
Scientific resources
List up to 5 known scientific resources that refer to the data set. Include review articles or
research articles that discuss topics and/or concepts related to the data. These articles
should be relevant to users who are working with the data set and need additional
background on the related science.
Scientific
Resources
Warming of the world ocean, 1955–2003. S. Levitus, J. Antonov, and T. Boyer.
Geophys. Res. Lett., 32, L02604, doi:10.1029/2004GL021592.
ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat05.pdf
New estimates of the variability of ocean heat content based on: a) additional data that extends the record to more
recent years; b) additional historical data for earlier years are presented . During 1955–1998 world ocean heat
content (0–3000 m) increased 14.5 _ 1022 J corresponding to a mean temperature increase of 0.037_C at a rate of
0.20 Wm_2 (per unit area of Earth’s total surface area).
Sea Level Rise During Past 40 Years Determined from Satellite and in Situ
Observations. Cabanes, C., et al. Science 26 October 2001: Vol. 294. no. 5543, pp.
840 – 842 DOI: 10.1126/science.1063556
http://www.sciencemag.org/cgi/content/full/294/5543/840?maxtoshow=&HIT
S=10&hits=10&RESULTFORMAT=&titleabstract=Sea+Level&searchid=100704600
6605_34779&stored_search=&FIRSTINDEX=0&fdate=10/1/2000&tdate=11/30/
2001
The 3.2 ± 0.2 millimeter per year global mean sea level rise observed by the Topex/Poseidon satellite over 1993-98
is fully explained by thermal expansion of the oceans. For the period 1955-96, sea level rise derived from tide gauge
data agrees well with thermal expansion computed at the same locations. However, we find that subsampling the
thermosteric sea level at usual tide gauge positions leads to a thermosteric sea level rise twice as large as the "true"
global mean. As a possible consequence, the 20th century sea level rise estimated from tide gauge records may have
been overestimated.
Sea level is rising: Do we know why? Mark F. Meier and John M. Wahr. PNAS. May
14, 2002, vol. 99, no. 10, 6524–6526.
http://www.pnas.org/cgi/reprint/99/10/6524
COMMENTARY: The gradual rise of sea level is one of the most troubling aspects of global change, especially
because it is likely to accelerate in the future as global warming progresses. Understanding the linkage between
warming climate and sea-level rise therefore is important and has been the subject of much study. Two processes
are involved: an increase of the mass of water in the oceans (the eustatic component), derived largely from the
melting of ice on land, and an increase of the volume of the ocean without change in mass (the steric component),
largely caused by the thermal expansion of ocean water. Neither of these components is understood fully, and
observations are not sufficient yet to develop a precise assessment of the causes of present-day sea-level rise let
alone a projection of future rise. In fact many of the analyses produce conflicting results.
Warming of the World Ocean: Scientific Interest in Ocean Heat Content. From
“NOAA Celebrates 200 Years of Science, Service and Stewardship.”
http://celebrating200years.noaa.gov/breakthroughs/warming_ocean/welcome.h
tml#interest
Anthropogenic warming of Earth’s climate system. Levitus, et al. Science 13 April
2001: Vol. 292. no. 5515, pp. 267 – 270 DOI: 10.1126/science.1058154
http://www.sciencemag.org/cgi/content/abstract/292/5515/267
“We compared the temporal variability of the heat content of the world ocean, of the global atmosphere, and of
components of Earth's cryosphere during the latter half of the 20th century. Each component has increased its heat
content (the atmosphere and the ocean) or exhibited melting (the cryosphere). The estimated increase of observed
global ocean heat content (over the depth range from 0 to 3000 meters) between the 1950s and 1990s is at least one
order of magnitude larger than the increase in heat content of any other component. Simulation results using an
atmosphere-ocean general circulation model that includes estimates of the radiative effects of observed temporal
variations in greenhouse gases, sulfate aerosols, solar irradiance, and volcanic aerosols over the past century agree
with our observation-based estimate of the increase in ocean heat content. The results we present suggest that the
observed increase in ocean heat content may largely be due to the increase of anthropogenic gases in Earth's
atmosphere.”
Sea level change through the last glacial cycle. Lambeck and Chappell. Science
April 27, 2001: Vol. 292, pp. 679-686.
Heading for Use in Teaching and Learning
Give a generalized heading for the Science Topics and Data-use skills sections. Use a
sentence of the form: These data can be used to teach or learn the following topics and
skills in ‘x’ (where ‘x’ is one or more disciplinary area).
Use in Teaching
and learning
This data can be used to teach or learn the following topics and skills in physical
or environmental oceanography:
Global scale oceanography
Global climate variations
Ocean study methodology
Graphic representation of data
Interpretation of data
Specific Topics
List specific science topics that might be addressed by exploring the data set. Topics are
issues or questions that can typically be addressed within one or two lecture periods.
Teaching
Topics
Global sea level change
Global ocean-climate interactions
Environmental impacts
Data-use skills
List specific data-use skills that student may exercise in working with the data set.
Data-use Skills
Using global oceanographic data to depict large-scale spatial and temporal trends
Educational resources
List known educational resources that refer to or utilize this data set. These include
references to papers or links to websites that describe instances of using the data in
learning activities.
Education
Resources
How Stuff Works: How do they measure sea level?
Earth Science/Oceanography – overviews concepts
http://science.howstuffworks.com/question356.htm
Data in the Classroom (developed for the NOAA Data Education Project)
Teacher Curriculum Guide and Student Activities
Understanding Sea Level Using Real Data (contains interactive exercises for
understanding sea level using satellite altimetry data, measuring storm effects and tide
data)
http://www.dataintheclassroom.org/content/sea-level/
Ocean World
Fisheries, weather, icebergs, waves, satellites, coral reefs, currents……
http://oceanworld.tamu.edu/
Potential consequences of climate variability and change. Global Climate Change:
A series of ten classroom-tested activities on the potential consequences of climate
variability and change, produced in cooperation with the Institute for Global
Environmental Strategies. (Grades 1-12)
http://octopus.gma.org/climate_change/index.html
Other related links
List additional websites that refer to the data set but don’t fit within other sections.
Other related
links
Where's the Heat? Think 'Deep Blue'
Brief NASA article on ocean temperatures
http://www.nasa.gov/centers/jpl/news/feature-ocean-heat.html
NOAA Education: Oceans and Coasts
These items are designed for the teacher to use in the classroom or as background
reference material. There is also information about programs that provide training
and other opportunities for educators. Multiple links to educational resources
including NOAA’s Ocean Explorer, and various other downloadable tutorials for
educators.
http://www.education.noaa.gov/tocean.html
Mechanisms that Can Cause Abrupt Climate Change
NOAA National Climactic Data Center site with very good overview of climate
transitions, possible causes, and is illustrated with excellent graphics.
http://www.ncdc.noaa.gov/paleo/abrupt/story.html
Climate Change Education.Org
Portal website dedicated to global warming education, climate change education.
Very large resources directory including related links to PBS productions from
NOVA and Frontline. K-12 and university level as well as general interest.
http://climatechangeeducation.org/
U.S. Global Change Research Information Office – Environmental Education
and Outreach
Portal website with various links and descriptions to climate change educational
resources.
http://www.gcrio.org/edu/index.htm
Global Warming/Climate Change Theme Page
This "Theme Page" has links to two types of resources related to the study of global
warming / climate change. Students and teachers will find curricular resources
(information, content...) to help them learn about this topic. In addition, there are
also links to instructional materials (lesson plans) which will help teachers provide
instruction in this theme.
http://www.cln.org/themes/global_warming.html
Seafloor to Surface to Satellite to Shore (Detrick et al., 2000)
Oceanus Article: Moored buoys offer potential for continuous, real-time observation
anywhere in the ocean
http://www.whoi.edu/oceanus/viewArticle.do?id=2432