Rtuffli: SIGNAL publish from draft v150

2026-05-30T18:55:26Z

SIGNAL publish from draft v150

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{| class="wikitable" style="float:right; clear:right; margin:0 0 1em 1em; width:320px;"
|+ SIGNAL Earth Structured Data
|-
! Object type
| Damage Signal
|-
! SIGNAL Earth ID
| DS-00123
|-
! Observable type
| Ice sheet mass
|-
! Unit
| Gt (gigatons of ice mass)
|-
! Temporal structure
| Periodic
|-
! Monitoring backbone
| —
|}


{{SignalTerm|type=DS|id=DS-00123|label=Ice sheet mass}} refers to the total amount of solid ice contained within the Earth's major ice sheets, primarily those covering Greenland and Antarctica. These massive accumulations of frozen water play a critical role in the global climate system by influencing sea level, albedo, and atmospheric circulation. The state of ice sheet mass is an important indicator of cryospheric health and climate variability.

Changes in ice sheet mass result from the balance between accumulation processes, such as snowfall, and ablation processes, including surface melting and iceberg calving. Monitoring these changes provides insight into ongoing climate dynamics and potential impacts on global sea levels. Understanding ice sheet mass variations is essential for projecting future climate scenarios and assessing environmental risks.

Within the broader context of Earth system science, ice sheet mass integrates observations from glaciology, climatology, and oceanography. It is a key variable in assessing the state of the cryosphere and its interaction with other environmental components.

== Geographic / System Context ==
The geographic scope of ice sheet mass encompasses the Greenland and Antarctic ice sheets, which together hold the vast majority of the Earth's freshwater ice. The Greenland ice sheet covers roughly 1.7 million square kilometers, while the Antarctic ice sheet spans about 14 million square kilometers. These ice sheets are situated in polar regions characterized by cold temperatures and unique atmospheric and oceanic conditions.

The mass of these ice sheets is influenced by regional climate patterns, including temperature, precipitation, and ocean currents. The Antarctic ice sheet is further subdivided into the East and West Antarctic regions, each exhibiting distinct glaciological behaviors. The Greenland ice sheet, located in the Arctic, is subject to different climatic influences, including Arctic amplification effects. Both ice sheets interact with surrounding ocean basins, affecting and being affected by marine and atmospheric processes.

== Monitoring and Measurement ==
Scientists monitor ice sheet mass using a combination of remote sensing technologies, in situ measurements, and modeling approaches. Satellite missions such as [https://en.wikipedia.org/wiki/NASA NASA]'s Gravity Recovery and Climate Experiment (GRACE) and its follow-on missions measure changes in Earth's gravity field to infer mass variations in ice sheets. Satellite altimetry instruments, including radar and laser altimeters, track changes in ice sheet surface elevation.

Ground-based observations, such as ice core drilling and GPS measurements, provide complementary data on ice dynamics and accumulation rates. Climate and glaciological models assimilate observational data to estimate mass balance and project future changes. International scientific organizations and agencies, including NASA and the European Space Agency, coordinate monitoring efforts to maintain continuous and comprehensive datasets.

Within the SIGNAL system, this phenomenon is treated as a defined environmental signal whose boundaries and measurement conventions are described below.

== Signal Definition ==
The {{SignalTerm|type=DS|id=DS-00123|label=Ice sheet mass}} damage signal is derived from the Observable Type 'Ice sheet mass' (OT-143) and represents the state condition of the cryosphere's major ice sheets. It quantifies the total mass of ice contained within the Greenland and Antarctic ice sheets, expressed in gigatonnes (Gt). This signal captures periodic changes in ice sheet mass driven by climatic and environmental factors, reflecting the net balance of accumulation and ablation processes.

== Boundary Conditions ==
Boundary inclusions encompass all solid ice mass within the geographic extents of the Greenland and Antarctic ice sheets, including grounded ice and ice shelves directly connected to these ice sheets. The signal excludes seasonal snow cover outside the ice sheet boundaries, floating sea ice, glaciers and ice caps not contiguous with the main ice sheets, and permafrost ice.

Temporal boundaries correspond to periodic assessments aligned with satellite overpass schedules and observational campaigns, typically on annual or sub-annual timescales. Spatial boundaries are defined by the recognized limits of the ice sheets as delineated by glaciological and geographic criteria.

== Aggregation Semantics ==
Geographically, ice sheet mass is aggregated over the entire Greenland and Antarctic ice sheets, with potential subdivision into regional sectors such as East and West Antarctica or peripheral glaciers for detailed analysis. Temporal aggregation follows periodic intervals, often annual, to capture seasonal and interannual variability.

Cross-signal aggregation involves integrating ice sheet mass data with related environmental signals such as global mean sea level and global mean [https://en.wikipedia.org/wiki/Sea_surface_temperature sea surface temperature]. This integration supports comprehensive assessments of cryosphere-ocean-atmosphere interactions and their influence on global climate systems. Aggregation methods prioritize consistency in spatial delineation and temporal resolution to ensure comparability across datasets.

== Observational Status ==
Monitoring of ice sheet mass is ongoing with increasing temporal and spatial resolution due to advances in satellite remote sensing and modeling. Data from missions like GRACE provide critical insights into mass balance trends from the early 1990s to the present. However, challenges remain in resolving fine-scale processes and isolating specific drivers of mass change.

Future SIGNAL releases may incorporate enhanced datasets from new satellite missions, improved ground-based observations, and refined modeling outputs. These developments will support more detailed temporal and spatial analyses, improving understanding of ice sheet dynamics and their role in the Earth system.

== Related Signals ==
* Global mean sea level
* Sea surface temperature (global mean)


== Key Associated People ==
* '''Inès N. Otosaka''' (University of Leeds) [Lead author]



== Sources ==
* [https://essd.copernicus.org/articles/15/1597/2023/ Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020 — 2023]

Ice sheet mass - Revision history

Rtuffli: SIGNAL publish from draft v150