Atmospheric Processes

Ice and Snow Dynamics

Ice and Snow Dynamics involve interactions of the atmosphere, cryosphere, hydrosphere, and lithosphere. The cryosphere, a term derived from the Greek word kryo for "cold" or "too cold", is the term which collectively describes the portions of the Earth where water is in solid form, including sea ice, lake ice, river ice, snow, glacier ice, glaciers, ice caps, ice sheets, and frozen ground (including permafrost.) The cryosphere is an integral part of the Earth system with important linkages and feedbacks generated through its influence on surface energy and moisture fluxes, clouds, precipitation, hydrology, and atmospheric and oceanic circulation. Subtle changes in ice and snow covered regions are known to be early indicators of and may be precursors to a changing global environment. The mass balance and dynamics of glaciers, ice caps, ice sheets, and changes in global sea level are of particular environmental interest.

The cryosphere, sea ice, glaciers, ice caps, snowpacks and permafrost, are critical components of the global climate system, with complex interactions and feedback mechanisms that affect not only the polar regions, but also the temperate portions of the Earth. Changes in these components are precursors to a changing global environment with poorly known environmental and societal impacts. Remote sensing products that are currently available in the public domain are beginning to provide the polar research community with information useful for examining a variety of climate change issues. However, much of these data are limited in both spatial and temporal resolution. Greater spatial resolution and geodetic precision, accurate ephemeris information, and historical data are needed to accurately assess the response of sea ice, glaciers and snowpacks to already documented changes in climate, which will be used to validate global climate models, thus providing more accurate climate change predictions.

High-resolution remotely sensed data, especially the archived imagery acquired under the MEDEA Program, will provide invaluable and unique insight into many cryospheric processes, which will allow the scientific community to better understand the global climate system. The data collected by these systems over the long-term, at a number of long-term ecological research areas, will help future generations answer questions of critical importance to environmental science and societal needs. The data from these remote sensing platforms, with its high spatial resolution and ability to revisit remote areas, combined with a long time series of high resolution images, offers unique opportunities for detailed studies of sea ice characteristics, glacial wastage and glacier dynamics, and snow pack extent, thickness and hydrology. Hence, the release of these data to the scientific community would be invaluable.

Geologic Processes

Geologic Processes involve interactions of the atmosphere, biosphere, cryosphere, hydrosphere, and lithosphere. The USGS defines Geologic Processes as all types of processes affecting geologic structures. These include: diagenesis, Earthquakes, erosion, glaciation, hydrothermal processes, isostacy, land subsidence, liquefaction, metamorphism, sediment transport, sedimentation, tectonic processes, volcanic activity, Earth tides, deformation, soil formation, magnetic storms, and mass wasting. Earth's ecosystems are affected by hazards to life and property caused by such phenomenon as volcanic eruptions, Earthquakes, Earth movements and tsunamis. Evaluation of these processes requires a variety of spatial, spectral, temporal and topographic data across a wide range of resolutions and areal extents.

Global Fiducials Library (GFL)

The Global Fiducials Library (GFL) is a long-term archive of images from U.S. National Imagery Systems which represents a long-term periodic record for selected scientifically important sites. The GFL was created to be the collection, archive and data management component of the Global Fiducials Program (GFP).

The GFP is a collaborative effort between Federal Civil Agencies, Academia, and the Intelligence Community. The principal goal of the GFP was to build and maintain a long-term record of data to support scientists and policy makers involved in that collaborative effort. At the inception of the Program, it was hoped that at some point - perhaps as much as twenty-five years into the future - the acquired data could be openly released to support future scientists and policy makers as well. Since the 1990s, the GFP has been periodically collecting images of environmentally significant sites around the world.

The GFL is managed by the U.S. Geological Survey under the National Civil Applications Program, in partnership with the Civil Applications Committee. The GFL archive is dedicated to ensuring that images of these selected sites are collected, maintained and made available to scientists and policy makers in support of scientific investigations into global dynamic systems and change. Until recently, use of these data was limited to an intelligence environment. Now, in what constitutes a change in the programmatic time line, the goal of the GFP is to make this extensive collection of images publicly available. This has been accomplished through the generation of unrestricted imagery derived products provides a high value way to offer valuable select imagery products to the scientific community. Essentially, the GFP is a proactive effort to "plan ahead for hindsight."

Ocean Processes

Ocean Processes involve interactions of the atmosphere, biosphere, cryosphere, hydrosphere, and lithosphere. Ocean Processes are defined by the USGS to include recurrent natural changes that are physical, biological, or chemical, actively affecting the seas and oceans. Among these are ocean circulation, ocean currents, tides, ocean waves, sea ice, coastal erosion and deposition, and marine pollution. The key to study of the Ocean Processes is the collection of a well documented suite of oceanographic images, collected with requisite sampling rates and calibration. This is the premise of the GFL.

Land Use/Land Cover

Land Use/Land Cover involve interactions of the atmosphere, biosphere, cryosphere, hydrosphere, and lithosphere. Land use and land cover are linked to climate and other environmental changes in complex ways, such as the exchange of greenhouse gases between plants and soils and the atmosphere, the effects of changes in land use and land cover on Earth's heat balance, and the impacts of changing environmental conditions on terrestrial ecosystems and biodiversity. Past land cover changes, such as the transitions from deglacierized bedrock to forest are important to understanding past climate variability and change, and projections of future land cover change are needed as input to models of future climate changes. Changes in land use and land cover affect ecosystems, biodiversity, agricultural productivity, and other goods and services of value to society. Many changes are the result of human activities.