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Description

This dataset contains in situ profile measurements from Airborne eXpendable Conductivity Temperature Depth (AXCTD) probes. It provides salinity, density, temperature and sound velocity as a function of depth in the water column. The AXCTDs were jettisoned from a plane to collect temperature and salinity readings around Greenland, where a ship would have had difficulties maneuvering. After landing in the water, the AXCTDs drop a weighted sensor from the surface that falls at a well-calibrated rate, measuring water temperature and conductivity as it falls. An equation is used to determine the depth of the measurements as the probe falls, and another equation is used to convert temperature, depth and conductivity into salinity. These probes provided measurements of the ocean's physical characteristics around Greenland, where a ship would have had difficulties maneuvering. The AXCTDs are part of the Oceans Melting Greenland (OMG) mission. The AXCTDs were deployed in the fall from 2016 through 2021, covering the entire continental shelf surrounding Greenland as part of a once-per-year survey. The goal of the mission is to find out what contributions the ocean has on Greenland's melting glaciers.

Product Summary

Platforms
AIRCRAFT
Instruments
AXCTD
Spatial Extent

N: 83.6 S: 59.1 E: 180 W: 73.6

,

N: 83.6 S: 59.1 E: -6.9 W: -180

Location
GREENLAND
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2016-09-13 to 2021-12-31
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2205122616-POCLOUD
Data State
COMPLETE
Number of Files/Granules
1393
Processing Level
2
Published
Updated
Science Keywords
Density ,
TEMPERATURE PROFILES ,
Salinity ,
Conductivity

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

OMG. (2019). OMG AXCTD Profiles [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/OMGEV-AXCT1 Date Accessed: 2026-03-15

Documents

vessel from Oceans Melting Greenland project

Oceans Melting Greenland

Learn how the Oceans Melting Greenland (OMG) projects surveys Greenland’s glaciers and ice sheets and studies how the oceans and ice interact with each other.
Data in Action
Feb. 27, 2017
SHOWING 1 OF 1

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
conductivity sea water electrical conductivity mS cm-1 float -9999 0 to 60 1 N/A
density sea water density kg m-3 float -9999 999 to 1045 1 N/A
depth depth meters float -9999 0 to 5000 1 N/A
frame Represents the observed measurement, format unknown. A value of 00000000 indicates no data available. N/A string N/A N/A 1 N/A
lat Represents the latitude of the plane position when the probe was deployed which is an estimate of the actual location where the probe hit the surface of the water. degrees_north float -9999 -90 to 90 1 N/A
lon Represents the longitude of the plane position when the probe was deployed which is an estimate of the actual location where the probe hit the surface of the water. degrees_east float -9999 -180 to 180 1 N/A
profile_time Represents the time in seconds since the weighted probe was released from the floating buoy. Depth is calculated from this variable based on a standard formula. seconds float -9999 N/A 1 N/A
salinity sea water salinity 1e-3 float -9999 0 to 45 1 N/A
sound_velocity speed of sound in sea water m s-1 float -9999 1405 to 1560 1 N/A
temperature sea water temperature degrees_C float -9999 -2.2 to 35 1 N/A
time Represents the time the probe was deployed from the plane. seconds since 1970-01-01T00:00:00Z double -9999 N/A 1 N/A
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