On 16-18 June 2008 the US National Snow and Ice Data Center held a GLIMS workshop in Boulder, CO,... more On 16-18 June 2008 the US National Snow and Ice Data Center held a GLIMS workshop in Boulder, CO, USA, focusing on formulating procedures and best practices for operational glacier mapping using satellite imagery. Despite the progress made in recent years, there still remain many cases where automatic delineation of glacier boundaries in satellite imagery is difficult, error prone or timeconsuming. This workshop identified six themes for consideration by focus groups: (1) mapping clean ice and lakes; (2) mapping ice divides; (3) mapping debris-covered glaciers; (4) assessing changes in glacier area and elevation through comparisons with older data; (5) digital elevation model (DEM) generation from satellite stereo pairs; and (6) accuracy and error analysis.
An extensive collection of many Antarctic glaciological parameters is available for the polar sci... more An extensive collection of many Antarctic glaciological parameters is available for the polar science community upon request. The National Science Foundation's Office of Polar Programs funds the Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) to archive and distribute Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program. AGDC facilitates data exchange among Principal Investigators, preserves recently collected data useful to future research, gathers data sets from past research, and compiles continent-wide information useful for modeling and field work planning. Data sets are available via our web site, http://nsidc.org/agdc/. From here, users can access extensive documentation, citation information, locator maps, derived images and references, and the numerical data. More than 50 Antarctic scientists have contributed data to the archive. Among the compiled products distributed by AGDC are VELMAP and THERMAP. THERMAP is a compilation of over 600 shallow firn temperature measurements ('10-meter temperatures') collected since 1950. These data provide a record of mean annual temperature, and potentially hold a record of climate change on the continent. The data are represented with maps showing the traverse route, and include data sources, measurement technique, and additional measurements made at each site, i.e., snow density and accumulation. VELMAP is an archive of surface ice velocity measurements for the Antarctic Ice Sheet. The primary objective of VELMAP is to assemble a historic record of outlet glaciers and ice shelf ice motion over the Antarctic. The collection includes both PI-contributed measurements and data generated at NSIDC using Landsat and SPOT satellite imagery. Tabular data contain position, speed, bearing, and data quality information, and related references. Two new VELMAP data sets are highlighted: the Mertz Glacier and the Institute Ice Stream. Mertz Glacier ice velocity provides an upper limit for change in velocity for this glacier over the past decade. Two pairs of Landsat images were used to compare velocities from 2000-2001 to 1989-2000. No significant change in velocity is observed. A new ice discharge flux of 17.8 km3a-1 was determined, and basal melting at the grounding line was re-calculated at 11 m per year (Berthier et al., 2003, in press). Velocity data for the Institute Ice Stream was compiled at NSIDC using a Landsat images from 1986, 1989, and 1997. The data were recently used in a study outlining the velocity, mass balance, and morphology of the Institute ice stream and nearby Ronne ice shelf area. (Scambos et al., 2003, in review). The study indicates the Institute has regions with flow and morphology characteristics similar to the Ross Embayment ice streams. Ice velocity research contributes to understanding the mass balance and overall stability of the Antarctic Ice Sheet. The archiving of velocity data has proven to be a useful tool to the Antarctic science community, and VELMAP continues to grow as a valuable resource through PI contributions. If you have velocity data that you would like to contribute to the VELMAP archive please contact [email protected]. The velocity data used in the two studies presented here can be accessed on the VELMAP web site at http://nsidc.org/data/velmap.
Efforts to compile a comprehensive global glacier inventory, such as that being undertaken by the... more Efforts to compile a comprehensive global glacier inventory, such as that being undertaken by the Global Land Ice Measurements from Space (GLIMS) project, require ready access to high-resolution satellite imagery as well as tools for performing analyses on these data. In this paper we describe a study of ice extent and volume changes for the Petrov glacier system of the Akshiyrak Range in the interior Tien Shan of Central Asia. Glacier outlines were digitized from an orthorectified ASTER imagery using a freeware tool, GLIMSView. A digital elevation model (DEM) was extracted from an ASTER scene acquired in October 2002. From these results we determine ice area as a function of elevation using GIS tools. The resulting hypsography is then used in conjunction with field measurements of mass balance for another glacier in the same range to estimate the mass balance for the Petrov glacier as a function of observed equilibrium line altitude, and thus to predict how climate change will impa...
GLIMS (Global Land Ice Measurements from Space) is a collaborative project among approximately 40... more GLIMS (Global Land Ice Measurements from Space) is a collaborative project among approximately 40 international institutions, whose goal is to develop a database of information on the world's glaciers that enables the assessment of current world glacier extent and glacier change. The National Snow and Ice Data Center (NSIDC) is developing the information management system for GLIMS, the database for which has already been designed and is being implemented at NSIDC. This presentation addresses the scientific considerations that went into the design of the GLIMS database, which consists of more than twenty tables containing both time-dependent and time-independent data. The fundamental data unit in the database is the "glacier", in roughly the conventional sense, rather than contiguous ice masses. The design had several goals: 1) to store spatio-temporal data for many different types of glaciers around the world; 2) to be able to retrieve such data through many types of ...
GLIMS (Global Land Ice Measurements from Space) is an international project to survey a majority ... more GLIMS (Global Land Ice Measurements from Space) is an international project to survey a majority of the world's glaciers with the accuracy and precision needed to assess recent changes and determine trends in glacial environments. This will be accomplished by: comprehensive periodic satellite measurements, coordinated distribution of screened image data, analysis of images at worldwide Regional Centers, validation of analyses, and a publicly accessible database. The primary data source will be from the ASTER (Advanced Spaceborne Thermal Emission and reflection Radiometer) instrument aboard the EOS Terra spacecraft, and Landsat ETM+ (Enhanced Thematic Mapper Plus), currently in operation. Approximately 700 ASTER images have been acquired with GLIMS gain settings as of mid-2001. GLIMS is a collaborative effort with the United States Geological Survey (USGS), the National Aeronautics Space Adminstration (NASA), other U.S. Federal Agencies and a group of internationally distributed ...
Understanding changes in the climate and mass balance of the Antarctic ice sheet is crucial to un... more Understanding changes in the climate and mass balance of the Antarctic ice sheet is crucial to understanding current global climate trends. Mean annual surface temperature is a significant environmental factor that directly indicates short-term Antarctic climate change. Ice flow speed is a component of the overall mass balance, and changes indicate a response to long-term shifts in climate and basal conditions. Past and current data sets on these parameters contribute to understanding the mass balance and overall stability of the Antarctic ice sheet. In an effort to better understand past, present, and future temperatures and mass balance of the ice sheet, the Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) is developing two data set compilations: Antarctic "10 meter" Temperature Data (THERMAP): Firn temperature at a depth of around 10 meters gives a close estimate of the mean annual surface temperature at that location. However,...
Recent and upcoming satellite optical systems are notable for additions of or trends toward impro... more Recent and upcoming satellite optical systems are notable for additions of or trends toward improvements in: (1) spatial resolution, (2) spectral resolution, (3) spectral range, (4) radiometric resolution and calibration, (5) geometric fidelity, (6) stereo capabilities, (7) global land coverage, (8) frequency of repeat coverage, and (9) user control of scheduling and acquisition parameters of the sensor systems. In addition, there have been great improvements in data downlink capability and ground data processing, archival, and distribution systems needed to accomodate the improved satellite capabilities These factors open new perspectives for global glacier monitoring from space, which last but not least triggered the Global Land Ice Measurements from Space (GLIMS) project (www.glims.org). In the present contribution, we give a number of examples for recent glacier monitoring applications from space. Automatic detection, inventoring and tracking of glacier area changes are demonstr...
The Hyperion sensor is an imaging spectroradimeter with 220 spectral bands over the solar spectru... more The Hyperion sensor is an imaging spectroradimeter with 220 spectral bands over the solar spectrum. The instrument is on-board NASA's Earth Observing-1 (EO-1) satellite and has acquired numerous images over the Greenland ice sheet. We use Hyperion spectral data from the range 0.98 - 1.06 microns to compute the scaled area of spectral absorption feature that is centered at 1.03 microns. The scaled area of this ice absorption feature is highly correlated with the optically-equivalent snow grain size and thus can be used to quantitatively estimate grain size for homogeneously snow-covered pixels under clear sky conditions. We present Hyperion-derived snow grain size estimates for several locations on the Greenland ice sheet. Furthermore, estimates of spectral albedo are derived by using these snow grain size estimates as input to a radiative transfer model. Broadband albedo is computed by direct integration of the spectral albedo values and then compared with concurrent in situ mea...
Global Land Ice Measurements from Space (GLIMS) is an international project tasked with surveying... more Global Land Ice Measurements from Space (GLIMS) is an international project tasked with surveying a majority of the world's estimated 160,000 glaciers with data collected by the Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) instrument aboard the EOS Terra spacecraft and the Landsat Enhanced Thematic Mapper Plus (ETM+). With National Aeronautics and Space Administration (NASA) funding, the National Snow and Ice Data Center (NSIDC) has developed the GLIMS glacier database. The database includes temporal measurements of glacier length, area, boundaries, topography, surface velocity vectors, and snowline elevation. The database design, data transfer specification, and ingest module are complete. Simple user interfaces for data submission and ordering are being tested. We are working closely with the United States Geological Survey on the development of GLIMS analysis software called GLIMSView. New funding from NASA, expected to begin in the next few months, ...
While there are complete regional databases and incomplete global databases of Earth's glacie... more While there are complete regional databases and incomplete global databases of Earth's glaciers, there are currently no geographically complete global glacier databases. Recent advances in technology have enabled the international project entitled Global Land Ice Measurements from Space (GLIMS) to assemble a Geographic Information System (GIS) of satellite-image-derived information on glaciers and ice sheets for all of Earth. This GIS is being contributed to, and will be used by, an international network of glaciological researchers. GLIMS participants at the US National Snow and Ice Data Center (Boulder, CO) have designed and implemented a comprehensive relational database to store glacier outlines, velocity fields, snow lines, glacier facies, and many other glacier data and metadata. Global monitoring of glaciers through GLIMS, and population of the NSIDC database, is just beginning; the global network of GLIMS Regional Centers can now contribute data derived from high quality...
Snow, ice, and frozen ground impact a significant part of the earth's surface and natural cyc... more Snow, ice, and frozen ground impact a significant part of the earth's surface and natural cycles. Geographic information systems (GIS) are frequently used in studying and assessing the influence of environmental conditions on geophysical, ecological, or socioeconomic factors, but researchers, planners, and decision makers wishing to incorporate cryospheric information into GIS studies often must confront issues related to data formats, data accessibility, and data quality. The National Snow and Ice Data Center (NSIDC) is developing a repository of GIS resources that will simplify the process of identifying, obtaining, and incorporating appropriate cryospheric data into GIS studies. The initial thrust of this repository is base maps, georeferenced images, and other data layers that may be used to study interactions of cryospheric elements with the environment. Supportive narratives, in addition to existing metadata, will describe appropriate uses and explain competing products. S...
Estimates of mass balance for 2003 are used in conjunction with historical records of mass balanc... more Estimates of mass balance for 2003 are used in conjunction with historical records of mass balance, photographs and remotely sensed images to document changes in the mass balance and area of Arapaho Glacier for the period 1970 to 2003. Arapaho Glacier is one of 14 small glaciers located on the east side of the Continental Divide in the Colorado Front Range. There are also hundreds of semi-permanent snow patches in the area. Changes in the mass of glaciers and snow patches can provide information about how the regional water balance changes with climate. Measurements of snow accumulation and summer balance at Arapaho Glacier were made every 2 to 3 weeks between May and October of the 2003 season. These frequent measurements allow the close relationship between glacier regime and local climate conditions to be studied. In particular, the date when mass balance changes from positive to negative can be determined. In 2003, this change occurred in the first week of August. Glacier runoff...
A set of value-added data products (VAPs)is being developed at the National Snow and Ice Data Cen... more A set of value-added data products (VAPs)is being developed at the National Snow and Ice Data Center (NSIDC) from the along-flight multi-sensor data sets gathered during the IceBridge flights of the DC-8 and P-3 NASA aircraft. These new products co-locate data from the IceBridge sensor suite and derive useful analysis parameters using one or more of the data streams. There are two along-track data sets being developed at NSIDC, one intended to facilitate ice sheet dynamics investigations, and one to characterize ice sheet surface and near-surface processes. Ice dynamics along-track products currently incorporate data from the Airborne Topographic Mapper (ATM), Sanders Gravimeter, Multi-Channel Coherent Depth Sounder (MCORDS) ice-penetrating radar system, and Digital Mapping System (DMS) camera. Derived products currently include regional slope (four hundred meter horizontal scale) and driving stress. Ice-dynamics along-track products currently under development focus on comparisons ...
Recent and upcoming satellite optical systems are notable for additions of or trends toward impro... more Recent and upcoming satellite optical systems are notable for additions of or trends toward improvements in: (1) spatial resolution, (2) spectral resolution, (3) spectral range, (4) radiometric resolution and calibration, (5) geometric fidelity, (6) stereo capabilities, (7) global land coverage, (8) frequency of repeat coverage, and (9) user control of scheduling and acquisition parameters of the sensor systems. In addition,
The main source of uncertainty in knowledge of the global glacier regime is the limited number of... more The main source of uncertainty in knowledge of the global glacier regime is the limited number of direct mass balance observations. Since the spatial variability of glacier properties is huge the few benchmark glaciers chosen for continuous observations are unlikely to adequately represent the glacier system to which they belong. It is not feasible to suggest that the number of
Global Land Ice Measurements from Space (GLIMS) is an international project with the goal of surv... more Global Land Ice Measurements from Space (GLIMS) is an international project with the goal of surveying a majority of the world's estimated 160,000 glaciers. GLIMS uses data collected primarily by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra satellite and the LandSat Enhanced Thematic Mapper Plus (ETM+). The National Aeronautics and Space Administration (NASA) and
Digital elevation models (DEMs) produced from ASTER stereo imagery over glacierized terrain frequ... more Digital elevation models (DEMs) produced from ASTER stereo imagery over glacierized terrain frequently contain data voids, which some software packages fill by interpolation. Even when interpolation is applied, the results are often not accurate enough for studies of glacier thickness changes. DEMs are created by automatic cross-correlation between the image pairs, and rely on spatial variability in the digital number
An early and dramatic indicator of global climate change has been the recession of mountain glaci... more An early and dramatic indicator of global climate change has been the recession of mountain glaciers. The potential impacts on water resources and global sea level rise has led to an increased interest in accurate monitoring and assessment of glaciers worldwide. Past glacier inventories recorded scalar information such as area and terminus location for glaciers in easily accessible regions of
On 16-18 June 2008 the US National Snow and Ice Data Center held a GLIMS workshop in Boulder, CO,... more On 16-18 June 2008 the US National Snow and Ice Data Center held a GLIMS workshop in Boulder, CO, USA, focusing on formulating procedures and best practices for operational glacier mapping using satellite imagery. Despite the progress made in recent years, there still remain many cases where automatic delineation of glacier boundaries in satellite imagery is difficult, error prone or timeconsuming. This workshop identified six themes for consideration by focus groups: (1) mapping clean ice and lakes; (2) mapping ice divides; (3) mapping debris-covered glaciers; (4) assessing changes in glacier area and elevation through comparisons with older data; (5) digital elevation model (DEM) generation from satellite stereo pairs; and (6) accuracy and error analysis.
An extensive collection of many Antarctic glaciological parameters is available for the polar sci... more An extensive collection of many Antarctic glaciological parameters is available for the polar science community upon request. The National Science Foundation's Office of Polar Programs funds the Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) to archive and distribute Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program. AGDC facilitates data exchange among Principal Investigators, preserves recently collected data useful to future research, gathers data sets from past research, and compiles continent-wide information useful for modeling and field work planning. Data sets are available via our web site, http://nsidc.org/agdc/. From here, users can access extensive documentation, citation information, locator maps, derived images and references, and the numerical data. More than 50 Antarctic scientists have contributed data to the archive. Among the compiled products distributed by AGDC are VELMAP and THERMAP. THERMAP is a compilation of over 600 shallow firn temperature measurements ('10-meter temperatures') collected since 1950. These data provide a record of mean annual temperature, and potentially hold a record of climate change on the continent. The data are represented with maps showing the traverse route, and include data sources, measurement technique, and additional measurements made at each site, i.e., snow density and accumulation. VELMAP is an archive of surface ice velocity measurements for the Antarctic Ice Sheet. The primary objective of VELMAP is to assemble a historic record of outlet glaciers and ice shelf ice motion over the Antarctic. The collection includes both PI-contributed measurements and data generated at NSIDC using Landsat and SPOT satellite imagery. Tabular data contain position, speed, bearing, and data quality information, and related references. Two new VELMAP data sets are highlighted: the Mertz Glacier and the Institute Ice Stream. Mertz Glacier ice velocity provides an upper limit for change in velocity for this glacier over the past decade. Two pairs of Landsat images were used to compare velocities from 2000-2001 to 1989-2000. No significant change in velocity is observed. A new ice discharge flux of 17.8 km3a-1 was determined, and basal melting at the grounding line was re-calculated at 11 m per year (Berthier et al., 2003, in press). Velocity data for the Institute Ice Stream was compiled at NSIDC using a Landsat images from 1986, 1989, and 1997. The data were recently used in a study outlining the velocity, mass balance, and morphology of the Institute ice stream and nearby Ronne ice shelf area. (Scambos et al., 2003, in review). The study indicates the Institute has regions with flow and morphology characteristics similar to the Ross Embayment ice streams. Ice velocity research contributes to understanding the mass balance and overall stability of the Antarctic Ice Sheet. The archiving of velocity data has proven to be a useful tool to the Antarctic science community, and VELMAP continues to grow as a valuable resource through PI contributions. If you have velocity data that you would like to contribute to the VELMAP archive please contact [email protected]. The velocity data used in the two studies presented here can be accessed on the VELMAP web site at http://nsidc.org/data/velmap.
Efforts to compile a comprehensive global glacier inventory, such as that being undertaken by the... more Efforts to compile a comprehensive global glacier inventory, such as that being undertaken by the Global Land Ice Measurements from Space (GLIMS) project, require ready access to high-resolution satellite imagery as well as tools for performing analyses on these data. In this paper we describe a study of ice extent and volume changes for the Petrov glacier system of the Akshiyrak Range in the interior Tien Shan of Central Asia. Glacier outlines were digitized from an orthorectified ASTER imagery using a freeware tool, GLIMSView. A digital elevation model (DEM) was extracted from an ASTER scene acquired in October 2002. From these results we determine ice area as a function of elevation using GIS tools. The resulting hypsography is then used in conjunction with field measurements of mass balance for another glacier in the same range to estimate the mass balance for the Petrov glacier as a function of observed equilibrium line altitude, and thus to predict how climate change will impa...
GLIMS (Global Land Ice Measurements from Space) is a collaborative project among approximately 40... more GLIMS (Global Land Ice Measurements from Space) is a collaborative project among approximately 40 international institutions, whose goal is to develop a database of information on the world's glaciers that enables the assessment of current world glacier extent and glacier change. The National Snow and Ice Data Center (NSIDC) is developing the information management system for GLIMS, the database for which has already been designed and is being implemented at NSIDC. This presentation addresses the scientific considerations that went into the design of the GLIMS database, which consists of more than twenty tables containing both time-dependent and time-independent data. The fundamental data unit in the database is the "glacier", in roughly the conventional sense, rather than contiguous ice masses. The design had several goals: 1) to store spatio-temporal data for many different types of glaciers around the world; 2) to be able to retrieve such data through many types of ...
GLIMS (Global Land Ice Measurements from Space) is an international project to survey a majority ... more GLIMS (Global Land Ice Measurements from Space) is an international project to survey a majority of the world's glaciers with the accuracy and precision needed to assess recent changes and determine trends in glacial environments. This will be accomplished by: comprehensive periodic satellite measurements, coordinated distribution of screened image data, analysis of images at worldwide Regional Centers, validation of analyses, and a publicly accessible database. The primary data source will be from the ASTER (Advanced Spaceborne Thermal Emission and reflection Radiometer) instrument aboard the EOS Terra spacecraft, and Landsat ETM+ (Enhanced Thematic Mapper Plus), currently in operation. Approximately 700 ASTER images have been acquired with GLIMS gain settings as of mid-2001. GLIMS is a collaborative effort with the United States Geological Survey (USGS), the National Aeronautics Space Adminstration (NASA), other U.S. Federal Agencies and a group of internationally distributed ...
Understanding changes in the climate and mass balance of the Antarctic ice sheet is crucial to un... more Understanding changes in the climate and mass balance of the Antarctic ice sheet is crucial to understanding current global climate trends. Mean annual surface temperature is a significant environmental factor that directly indicates short-term Antarctic climate change. Ice flow speed is a component of the overall mass balance, and changes indicate a response to long-term shifts in climate and basal conditions. Past and current data sets on these parameters contribute to understanding the mass balance and overall stability of the Antarctic ice sheet. In an effort to better understand past, present, and future temperatures and mass balance of the ice sheet, the Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) is developing two data set compilations: Antarctic "10 meter" Temperature Data (THERMAP): Firn temperature at a depth of around 10 meters gives a close estimate of the mean annual surface temperature at that location. However,...
Recent and upcoming satellite optical systems are notable for additions of or trends toward impro... more Recent and upcoming satellite optical systems are notable for additions of or trends toward improvements in: (1) spatial resolution, (2) spectral resolution, (3) spectral range, (4) radiometric resolution and calibration, (5) geometric fidelity, (6) stereo capabilities, (7) global land coverage, (8) frequency of repeat coverage, and (9) user control of scheduling and acquisition parameters of the sensor systems. In addition, there have been great improvements in data downlink capability and ground data processing, archival, and distribution systems needed to accomodate the improved satellite capabilities These factors open new perspectives for global glacier monitoring from space, which last but not least triggered the Global Land Ice Measurements from Space (GLIMS) project (www.glims.org). In the present contribution, we give a number of examples for recent glacier monitoring applications from space. Automatic detection, inventoring and tracking of glacier area changes are demonstr...
The Hyperion sensor is an imaging spectroradimeter with 220 spectral bands over the solar spectru... more The Hyperion sensor is an imaging spectroradimeter with 220 spectral bands over the solar spectrum. The instrument is on-board NASA's Earth Observing-1 (EO-1) satellite and has acquired numerous images over the Greenland ice sheet. We use Hyperion spectral data from the range 0.98 - 1.06 microns to compute the scaled area of spectral absorption feature that is centered at 1.03 microns. The scaled area of this ice absorption feature is highly correlated with the optically-equivalent snow grain size and thus can be used to quantitatively estimate grain size for homogeneously snow-covered pixels under clear sky conditions. We present Hyperion-derived snow grain size estimates for several locations on the Greenland ice sheet. Furthermore, estimates of spectral albedo are derived by using these snow grain size estimates as input to a radiative transfer model. Broadband albedo is computed by direct integration of the spectral albedo values and then compared with concurrent in situ mea...
Global Land Ice Measurements from Space (GLIMS) is an international project tasked with surveying... more Global Land Ice Measurements from Space (GLIMS) is an international project tasked with surveying a majority of the world's estimated 160,000 glaciers with data collected by the Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) instrument aboard the EOS Terra spacecraft and the Landsat Enhanced Thematic Mapper Plus (ETM+). With National Aeronautics and Space Administration (NASA) funding, the National Snow and Ice Data Center (NSIDC) has developed the GLIMS glacier database. The database includes temporal measurements of glacier length, area, boundaries, topography, surface velocity vectors, and snowline elevation. The database design, data transfer specification, and ingest module are complete. Simple user interfaces for data submission and ordering are being tested. We are working closely with the United States Geological Survey on the development of GLIMS analysis software called GLIMSView. New funding from NASA, expected to begin in the next few months, ...
While there are complete regional databases and incomplete global databases of Earth's glacie... more While there are complete regional databases and incomplete global databases of Earth's glaciers, there are currently no geographically complete global glacier databases. Recent advances in technology have enabled the international project entitled Global Land Ice Measurements from Space (GLIMS) to assemble a Geographic Information System (GIS) of satellite-image-derived information on glaciers and ice sheets for all of Earth. This GIS is being contributed to, and will be used by, an international network of glaciological researchers. GLIMS participants at the US National Snow and Ice Data Center (Boulder, CO) have designed and implemented a comprehensive relational database to store glacier outlines, velocity fields, snow lines, glacier facies, and many other glacier data and metadata. Global monitoring of glaciers through GLIMS, and population of the NSIDC database, is just beginning; the global network of GLIMS Regional Centers can now contribute data derived from high quality...
Snow, ice, and frozen ground impact a significant part of the earth's surface and natural cyc... more Snow, ice, and frozen ground impact a significant part of the earth's surface and natural cycles. Geographic information systems (GIS) are frequently used in studying and assessing the influence of environmental conditions on geophysical, ecological, or socioeconomic factors, but researchers, planners, and decision makers wishing to incorporate cryospheric information into GIS studies often must confront issues related to data formats, data accessibility, and data quality. The National Snow and Ice Data Center (NSIDC) is developing a repository of GIS resources that will simplify the process of identifying, obtaining, and incorporating appropriate cryospheric data into GIS studies. The initial thrust of this repository is base maps, georeferenced images, and other data layers that may be used to study interactions of cryospheric elements with the environment. Supportive narratives, in addition to existing metadata, will describe appropriate uses and explain competing products. S...
Estimates of mass balance for 2003 are used in conjunction with historical records of mass balanc... more Estimates of mass balance for 2003 are used in conjunction with historical records of mass balance, photographs and remotely sensed images to document changes in the mass balance and area of Arapaho Glacier for the period 1970 to 2003. Arapaho Glacier is one of 14 small glaciers located on the east side of the Continental Divide in the Colorado Front Range. There are also hundreds of semi-permanent snow patches in the area. Changes in the mass of glaciers and snow patches can provide information about how the regional water balance changes with climate. Measurements of snow accumulation and summer balance at Arapaho Glacier were made every 2 to 3 weeks between May and October of the 2003 season. These frequent measurements allow the close relationship between glacier regime and local climate conditions to be studied. In particular, the date when mass balance changes from positive to negative can be determined. In 2003, this change occurred in the first week of August. Glacier runoff...
A set of value-added data products (VAPs)is being developed at the National Snow and Ice Data Cen... more A set of value-added data products (VAPs)is being developed at the National Snow and Ice Data Center (NSIDC) from the along-flight multi-sensor data sets gathered during the IceBridge flights of the DC-8 and P-3 NASA aircraft. These new products co-locate data from the IceBridge sensor suite and derive useful analysis parameters using one or more of the data streams. There are two along-track data sets being developed at NSIDC, one intended to facilitate ice sheet dynamics investigations, and one to characterize ice sheet surface and near-surface processes. Ice dynamics along-track products currently incorporate data from the Airborne Topographic Mapper (ATM), Sanders Gravimeter, Multi-Channel Coherent Depth Sounder (MCORDS) ice-penetrating radar system, and Digital Mapping System (DMS) camera. Derived products currently include regional slope (four hundred meter horizontal scale) and driving stress. Ice-dynamics along-track products currently under development focus on comparisons ...
Recent and upcoming satellite optical systems are notable for additions of or trends toward impro... more Recent and upcoming satellite optical systems are notable for additions of or trends toward improvements in: (1) spatial resolution, (2) spectral resolution, (3) spectral range, (4) radiometric resolution and calibration, (5) geometric fidelity, (6) stereo capabilities, (7) global land coverage, (8) frequency of repeat coverage, and (9) user control of scheduling and acquisition parameters of the sensor systems. In addition,
The main source of uncertainty in knowledge of the global glacier regime is the limited number of... more The main source of uncertainty in knowledge of the global glacier regime is the limited number of direct mass balance observations. Since the spatial variability of glacier properties is huge the few benchmark glaciers chosen for continuous observations are unlikely to adequately represent the glacier system to which they belong. It is not feasible to suggest that the number of
Global Land Ice Measurements from Space (GLIMS) is an international project with the goal of surv... more Global Land Ice Measurements from Space (GLIMS) is an international project with the goal of surveying a majority of the world's estimated 160,000 glaciers. GLIMS uses data collected primarily by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra satellite and the LandSat Enhanced Thematic Mapper Plus (ETM+). The National Aeronautics and Space Administration (NASA) and
Digital elevation models (DEMs) produced from ASTER stereo imagery over glacierized terrain frequ... more Digital elevation models (DEMs) produced from ASTER stereo imagery over glacierized terrain frequently contain data voids, which some software packages fill by interpolation. Even when interpolation is applied, the results are often not accurate enough for studies of glacier thickness changes. DEMs are created by automatic cross-correlation between the image pairs, and rely on spatial variability in the digital number
An early and dramatic indicator of global climate change has been the recession of mountain glaci... more An early and dramatic indicator of global climate change has been the recession of mountain glaciers. The potential impacts on water resources and global sea level rise has led to an increased interest in accurate monitoring and assessment of glaciers worldwide. Past glacier inventories recorded scalar information such as area and terminus location for glaciers in easily accessible regions of
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