Project Description

Lead Image

AVHRR Leads-ARI Polar Gridded Brightness Temperatures

IMPORTANT NOTE: Data for 1992 are currently being reprocessed and will be available in the near future. Please contact NSIDC User Services for more information.

Information in this document has been derived from:

Fetterer, F. M., and J. D. Hawkins. 1991. An AVHRR data set for the arctic leads ARI. Naval Oceanographic and Atmospheric Research Laboratory, Technical Note 118, 61 p.

Fetterer, F. M., and J. Hawkins. 1993. Data set of arctic AVHRR imagery for the study of leads. Annals of Glaciology. 17:394-404.


Summary

Ships and submarines have historically used leads, or sea ice fractures, to navigate Arctic waters. Scientists study leads to better understand their roles in arctic climatology and global climate change. Leads, particularly those exposing warm ocean water to cold arctic air, influence the energy balance at polar latitudes by contributing to the atmospheric heat flux. Because the poles act as heat sinks in the global energy balance, lead formation, evolution and distribution in the polar regions is important.

Satellite imagery provides invaluable views of leads to scientists interested in lead dynamics. For that reason, a data set of Advanced Very High Resolution Radiometer (AVHRR) imagery has been compiled as part of the Arctic Leads Accelerated Research Initiative ARI (Arctic Leads ARI). The Project Investigators for the Arctic Leads ARI Data Set evaluated hard copies of AVHRR imagery to select images for the data set. The raw data for selected images were converted to albedo and brightness temperature, and gridded to a stereographic projection. The data set consists of imagery for 1988, 1989, and 1992. Grids completely cover the Beaufort, Chukchi, East Siberian, Barents, and Kara Seas, and partially cover the East Greenland and Laptev Seas. The data set is available through NSIDC User Services.

For more information, please refer to the Arctic Leads ARI Data Set document and Instrument and Platform document.

Table of Contents

1. Project Overview
2. Data Availability
3. Data Access
4. Principal Investigator Information
5. Submitting Investigator Information
6. References
7. Acronyms and Abbreviations
8. Document Information

1. Project Overview

Name of Project

Office of Naval Research Arctic Leads Accelerated Research Initiative (ARI)

Project Introduction

The objective of the Arctic Leads ARI was to gain a better understanding of lead dynamics. As part of the project, the Arctic Leads ARI Data Set was created to encourage the assembly of an arctic leads climatology. The ARI was sponsored by the Office of Naval Research (ONR) and included the LeadEx field experiment in the spring of 1992.

The Arctic Leads ARI project was supported by ONR under Program Element No. 61153N with Dr. Thomas Curtin as Program Manager. Distribution of the data set is supported by NASA under its Earth Observing System Data and Information System (EOSDIS) program. Please refer to the acknowledgements made by the Principal Investigators for the data set project.

Project Mission Objectives

The goal of the five year Arctic Leads ARI was a more thorough understanding of the oceanography, meteorology, and ice dynamics surrounding lead formation and evolution.

Disciplines

The data set is of use to scientists investigating global climate change as well as oceanographers and meteorologists studying the Arctic region. Specifically, it has applications in the following areas:

Geographic Region

Images available for the Arctic area outlined on the Arctic Leads ARI Grid Map including the Beaufort, Chukchi, East Siberian, Barents, Kara, East Greenland, and Laptev Seas.

Detailed Project Description

In January 1989, a workshop was held at the University of Washington's Applied Physics Laboratory (UW/APL) to plan the Office of Naval Research (ONR) Arctic Leads Accelerated Research Initiative (Arctic Leads ARI). At this meeting, a Remote Sensing Working Group was formed to focus on leads issues including:

The Remote Sensing Working Group determined that a satellite data set was needed to support the science objectives outlined in their workshop report. The AVHRR was selected for its ability to acquire data with Arctic-wide views at a resolution useful for leads statistics retrieval. In September 1989, a discussion about the type of data set needed took place at the Cooperative Institute for Research in Environmental Sciences (CIRES). This discussion resulted in a successful Naval Oceanographic and Atmospheric Research Laboratory (NOARL, now a part of the Naval Research Laboratory) proposal to ONR for the creation of an AVHRR Arctic leads data set.

In April 1990, the Remote Sensing Branch of NOARL began selecting AVHRR data from NOAA archives. Using hard copy prints from the Navy/NOAA Joint Ice Center, the investigators selected imagery in an attempt to cover most of the Arctic every three days. The selected imagery was processed on a scale that allows for the observation of regional, seasonal, and annual variability in lead patterns. The raw data for the selected images were converted to albedo and brightness temperature, and the compiled data were gridded to a stereographic projection identical to that used for Special Sensor Microwave Imager (SSM/I) data by the National Snow and Ice Data Center. The data set includes imagery for 1989 through 1991 that covers the Arctic in two grids of 1-km pixels.

The LeadEx field component of ONR's Arctic Leads ARI was carried out in March and April of 1992 in the Beaufort Sea. The effect of open leads on the polar ocean and atmosphere was studied using data collected from a base camp northeast of Prudhoe Bay, Alaska and at several nearby leads using remote and in situ, surface-based sensors.

2. Data Availability

Data Type

The data set consists of both image files and graphics files, and also includes files with satellite nadir track positions.

Input/Output Media

The data set is available on either 8 mm or 4 mm tape. Selected images can be made available via ftp. For more information about output products and availability, please contact NSIDC User Services.

3. Data Access

Data Center Location

National Snow and Ice Data Center (NSIDC)

Contact Information

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Associated Costs

This field is intentionally left blank.

4. Principal Investigator Information

The Principal Investigators for the data set project of the Arctic Leads ARI were:

Florence M. Fetterer, National Snow and Ice Data Center

Jeffrey D. Hawkins, Prediction Systems Branch, Naval Research Laboratory, Marine Meteorology Division

5. Submitting Investigator Information

Jeff Key, Associate Professor, Department of Geography, Boston University

6. References

Fetterer, F. M., and J. D. Hawkins. 1991. An AVHRR data set for the arctic leads ARI. Naval Oceanographic and Atmospheric Research Laboratory, Technical Note 118, 61 p.

Fetterer, F. M., and J. Hawkins. 1993. Data set of arctic AVHRR imagery for the study of leads. Annals of Glaciology. 17:394-404.

7. Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

ARI Accelerated Research Initiative
AVHRR Advanced Very High Resolution Radiometer
CIRES Cooperative Institute for Research in Environmental Sciences
EOSDIS Earth Observing System Data and Information System
km Kilometer
NASA National Aeronautics and Space Administration
NOAA National Oceanic and Atmospheric Administration
NOARL Naval Oceanographic and Atmospheric Research Laboratory
NSIDC National Snow and Ice Data Center
ONR Office of Naval Research
SSM/I Special Sensor Microwave Imager
URL Uniform Resource Locator
UW/APL University of Washington Applied Physics Laboratory

8. Document Information

Revision Date: 03 January 1996, 22 May 2003
Review Date: 27 September 1995
Document ID: nsidc-0026
Document Curators: NSIDC Writers
Document URL: http://nsidc.org/data/docs/daac/arctic_leads_ari_campaign.gd.html