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S-band waveguide measurements of sea-ice samples ranging from 2.6 to 3.95 GHz during the SIPEX II voyage of the Aurora Australis, 2012

Entry ID: SIPEX_II_Waveguide

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Summary

Abstract: This dataset contains data relating to an experimental method in which sea-ice samples were measured in an S-band microwave waveguide. This was conducted as a part of the 2012 SIPEX 2 (Sea Ice Physics and Ecosystems EXperiment) marine science voyage.

A specially designed waveguide apparatus was connected to an Agilent FieldFox Portable Network Analyzer. Small parallelopipeds (7 cm X 3 cm X 1.9 ... cm) of sea ice were cut with a hand saw in a specially designed jig which holds an initially cylindrical core. The samples were placed at the end of the waveguide, configured to measure the vertical component of the effective complex permittivity tensor, and microwaves of frequency 2.9 GHz were sent down the tube. The samples were sized precisely to fit snugly in the end of the waveguide in order to minimize spurious reflections. The FieldFox recorded the coefficients of the scattering matrix, from which the complex permittivity can be computed. Sample temperature was taken both before and immediately after insertion into the waveguide.

In order to assess the presence of off-vertical components of the electromagnetic field and how they may affect the measurements, a second sample was prepared with an orthogonal orientation, adjacent to the first sample. The same microwave measurements were taken on the second sample, to be later correlated with those from the first sample.

The samples were stored in the freezer for later crystallographic analysis, and subsequently melted for salinity measurements. Prior to melting the samples were measured using callipers to determine their dimensions precisely. Samples were measured along each face at their minimum and maximum point for their width in the direction of propagation. In most cases samples were measured in all dimensions for better error analysis. A thin vertical section, approximately 5mm thick, was taken from each microwave sample stored for analysis. These sections were placed between a pair of cross polarized plates and photographed.

Photos of the crystallography cores can be found in the crystallography folder, in a sub folder titled microwave. Each photo also contains a tag indicating the core number, site taken, date, as well as a V or an H indicating whether the sample was used for measurement of the vertical (V) or off-vertical (H) response.

The scattering parameters recorded by the Field Fox can be found in the Data folder. Each file is named according to the microwave core measurement it represents and whether the measurement was of the vertical (V) or off-vertical (H) response. Each contains a standard S11 scattering parameter, stored as a comma separated value (CSV) file. Raw data can be found in the raw folder, and data that has been processed for ease of Matlab import can be found in the Reformatted_for_matlab folder. This processing involves taking output data that by default has four entries in a single column vector and remapping the data to create a four column matrix, each with a single entry.

Recorded values for each microwave sample can be found in the Master_Core_List.xls Excel spreadsheet, within the Microwave worksheet. This worksheet was generated directly from notebook data, and contains the date, core number, depth of interface between the two collected samples, the minimum, maximum, and average thickness along the axis of propagation, The recorded temperatures from before and after measurement, the salinity, and calculated brine volume fraction. Finally, the worksheet contains notes, and a column to indicate whether we believe this data is somehow bad. Measurement information for thicknesses along other axis than that of propagation can be found in notes, but this data may at some stage be incorporated into a separate column. Please see the notes section for reasons why a data point was determined invalid. Typically this was due to the corresponding sample breaking while cutting into the parallelepiped shape.

Scans of the original notebooks containing measured salinity values, thicknesses, and temperatures from which the Permeability worksheet were created are provided in the notebooks directory.

Related URL

Link: GET DATA

Description: Download point for the data

Geographic Coverage

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Spatial coordinates

N: -65.26

S: -65.29

E: 120.08

W: 119.93

N: -65.14

S: -65.26

E: 119.0

W: 118.32

N: -64.68

S: -64.87

E: 116.83

W: 115.71

Parent DIF

This data set description is a member of a collection. The collection is described in
SIPEX_II

Temporal Coverage

Start Date: 2012-10-14

Stop Date: 2012-10-31

Location Keywords

OCEAN > SOUTHERN OCEAN

CONTINENT > ANTARCTICA

GEOGRAPHIC REGION > POLAR

Science Keywords

CRYOSPHERE > SEA ICE

CRYOSPHERE > SEA ICE > ICE TEMPERATURE

OCEANS > SEA ICE

OCEANS > SEA ICE > ICE TEMPERATURE

ISO Topic Category

CLIMATOLOGY/METEOROLOGY/ATMOSPHERE

GEOSCIENTIFIC INFORMATION

OCEANS

Platform

AQUA > Earth Observing System, AQUA

Instrument

MODIS > Moderate-Resolution Imaging Spectroradiometer

Project

EOS > Earth Observing System

EOSDIS > Earth Observing System Data Information System

ESIP > Earth Science Information Partners Program

Quality For data quality information on MODIS SST products performed by the Ocean
Biology Processing Group (OBPG) see
http://oceancolor.gsfc.nasa.gov/DOCS/modis_sst/

Access Constraints None

Use Constraints Publications of research results utilizing these data must acknowledge the
Ocean Biology Processing Group (OBPG) at the NASA Goddard Space Flight Center,
Greenbelt, MD, USA.

Data Set Progress

IN WORK

Originating Center

OBPG

Data Center

Ocean Biology Processing Group (OBPG), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA

Data Center URL: http://oceancolor.gsfc.nasa.gov/

Data Center Personnel
Name: GENE CARL FELDMAN Phone: (301) 286-9428 Fax: (301) 286-0268 Email: gene.c.feldman at nasa.gov Contact Address: Data System Manager NASA/Goddard Space Flight Center Mailstop 614.8 City: Greenbelt Province or State: MD Postal Code: 20771 Country: USA