Ice ablation process subclasses

[kaiiam]

During the VoCamp Glacier Ontology Hackathon there was discussion about how best to capture the semantics of an ablation process, given that there were partially different definitions given by the NOAA National Weather Service (2009) glossary and the Cogley et al. (2011) IACS-UNESCO Glacier Mass Balance glossary.

To accommodate these definitional discrepancies I propose the following as subclasses of ENVO:ice ablation process [ENVO_01000919]:

1) ENVO:icemelt-derived ice ablation process defined as:

An ice ablation process during which ice is lost due to an icemelt process.

with subclass axioms:

ENVO:ice ablation process [ENVO_01000919]

BFO:has part [BFO_0000051] some ENVO:icemelt [ENVO_01000721]

oboInOwl:database_cross_reference [hasDbXref] http://w1.weather.gov/glossary/.

2) ENVO:icemelt or calving-derived ice ablation process defined as:

An ice ablation process during which ice is lost due to an icemelt process or ice calving process.

with subclass axioms:

ENVO:ice ablation process [ENVO_01000919]

BFO:has part [BFO_0000051] some (ENVO:icemelt [ENVO_01000721] or ENVO:ice calving process [ENVO_01000917])

oboInOwl:database_cross_reference [hasDbXref] http://unesdoc.unesco.org/images/0019/001925/192525e.pdf.

[rduerr]

Hi Kai,

Actually the situation is more nuanced than just those two definitions. Here is the set of definitions from all the cryospheric glossaries in the GCW compilation I am working on, as well as my comments on the set. I hope this is useful to you.

Ablation NOAA Glossary of Hydrologic Terms Snow The process by which ice and snow dissipate owing to melting and evaporation.
There are three main inconsistencies to resolve with this set of definitions:

1. Prior to 1980, the term ablation was not used to describe mechanical processes for removal of snow or ice (e.g., wind erosion, avalanches, calving, etc.) so many definitions do not include these processes. Resolving this might include splitting the term into a pre-1980 version and a post-1980 version. Alternately a single term with the more inclusive meaning could be used if the community does not object. A semantic annotation to the effect that the definition was different prior to 1980 should be made in any ontology using the term.

2. The term is used both as a process and as an amount of mass removed. Semantically speaking these are two distinct concepts (e.g., ablation results in ablation_amount of ice loss), though ablation_amount would more likely be an attribute.

3. Semantically speaking it is problematic to use the term ablation as if it were a synonym of surface ablation, when there are other types of ablation (e.g., internal ablation, basal ablation, frontal ablation, etc.). Some definitions do this as well (e.g., NSIDC accessed 2016). In general, it looks like this is related to the purpose or generality of the glossary from which the term came; so may be an easy issue to resolve.

Other issues:

a. Some definitions include only snow and ice; while others include "water in any form". How to handle this depends on the resolution to the inconsistencies above.

b. Some definitions state that ablation is a process affecting only glaciers, or only glaciers and snow-fields, or only snow cover, or glaciers, floating ice or snow cover. How to handle this depends on the resolution to the inconsistencies above.

c. Some definitions include additional discussion of the the physics involved which would be useful for connecting glacier ontologies to atmospheric, solar, etc. ontologies. This information should be captured no matter how the inconsistencies above are resolved. NSIDC accessed 2016 Snow (1) combined processes (such as sublimation, fusion or melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field; also used to express the quantity lost by these processes (2) reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches. Cogley et al. IACS-UNESCO Glacier Mass Balance 2011 Snow (1) All processes that reduce the mass of the glacier. (2) The mass lost by the operation of any of the processes of sense 1, expressed as a negative number. The main processes of ablation are melting and calving (or, when the glacier nourishes an ice shelf, ice discharge across the grounding line). On some glaciers sublimation, loss of windborne snow and avalanching are significant processes of ablation. 'Ablation', unqualified, is sometimes used as if it were a synonym of surface ablation, although internal ablation, basal ablation, and frontal ablation, especially calving, can all be significant in some contexts. Molnia USGS 2004 Snow Ablation refers to all processes by which snow, ice, or water in any form are lost from a glacier. Ablation is the loss of snow or ice by evaporation and melting. The rate at which ablation occurs depends on the atmospheric conditions present, such as air moisture content, solar radiation, temperature, and the reflectivity (Albedo) of the snow or ice surface. Fresh snow has a high albedo (0.7 to 0.9), indicating that 70 to 90 percent of the radiation received is reflected; glacier ice has a lower albedo of 0.2 to 0.4. Therefore, more radiation may be absorbed by glacier ice than by snow. Glaciers around the mountain receive different amounts of sunlight, so each glacier has its own characteristic ablation pattern. Molnia USGS 2004 Snow The loss of ice and snow from a glacier system. This occurs through a variety of processes including melting and runoff, sublimation, evaporation, calving, and wind transportation of snow out of a glacier basin. Fierz et al. IACS-UNESCO Seasonal Snow on the Ground 2009 Snow All processes that remove snow, ice, or water from a snowfield, glacier, etc., that is typically melt, evaporation, sublimation as well as wind erosion, avalanches, calving, etc.; in this sense, the opposite of accumulation. In many publications before 1980, ablation did not include mechanical removal of either snow or ice, i.e., wind erosion, avalanches, calving, etc. NOAA National Weather Service Glossary 2009 Snow Depletion of snow and ice by melting and evaporation. WMO METEOTERM accessed 2016 Snow (1) Combined processes (such as sublimation, melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field. Also used to express the quantity lost by these processes. (2) Reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches. Environment and Climate Change Canada 2014 Snow Reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches. UNESCO-WMO International Glossary of Hydrology 2012 Snow (1) Combined processes (such as melting, sublimation, evaporation or calving) which remove snow or ice from a glacier or from a snowfield; also used to express the quantity lost by these processes. (2) Reduction of the water equivalent of snow cover by melting, evaporation, wind and avalanches. Swisseduc - Photo glossary of glaciological terms Snow The process of wastage of snow or ice by melting, sublimation and calving. AMS - glossary of meteorology Snow 1. All processes that remove snow, ice, or water from a glacier, snowfield, etc.; in this sense, the opposite of accumulation. These processes include melting, evaporation, calving, wind erosion, and an avalanche. Air temperature is the dominant factor in controlling ablation, precipitation amounts exercising only secondary control. During the ablation season (usually summer), an ablation rate of about 2 mm/h is typical of glaciers in a temperate climate. 2. The amount of snow or ice removed by the above-described processes; in this sense, the opposite of accumulation. PhysicalGeography.net http://physicalgeography.net/ Snow Surface removal of ice or snow from a glacier or snowfield by melting, sublimation, and/or calving. Illustrated Glossary of Snow and Ice Snow All processes by which snow, ice, or water in any form are lost from a glacier, floating ice or snow cover. These include melting, evaporation, calving, wind erosion and avalanches. Also used to express the quantity lost by these processes.

Ruth

On Mar 12, 2018, at 3:00 AM, Kai Blumberg notifications@github.com wrote:

During the VoCamp Glacier Ontology Hackathon https://github.com/Vocamp/Virtual-Hackahon-on-Glacier-topic there was discussion about how best to capture the semantics of an ablation process, given that there were partially different definitions given by the NOAA National Weather Service (2009) glossary http://w1.weather.gov/glossary/ and the Cogley et al. (2011) IACS-UNESCO Glacier Mass Balance glossary http://unesdoc.unesco.org/images/0019/001925/192525e.pdf.

To accommodate these definitional discrepancies I propose the following as subclasses of ENVO:ice ablation process [ENVO_01000919]:

ENVO:icemelt-derived ice ablation process defined as: An ice ablation process during which ice is lost due to an icemelt process.

with subclass axioms:

ENVO:ice ablation process [ENVO_01000919]

BFO:has part [BFO_0000051] some ENVO:icemelt [ENVO_01000721]

oboInOwl:database_cross_reference [hasDbXref] http://w1.weather.gov/glossary/ http://w1.weather.gov/glossary/.

ENVO:icemelt or calving-derived ice ablation process defined as: An ice ablation process during which ice is lost due to an icemelt process or ice calving process.

with subclass axioms:

ENVO:ice ablation process [ENVO_01000919]

BFO:has part [BFO_0000051] some (ENVO:icemelt [ENVO_01000721] or ENVO:ice calving process [ENVO_01000917])

oboInOwl:database_cross_reference [hasDbXref] http://unesdoc.unesco.org/images/0019/001925/192525e.pdf http://unesdoc.unesco.org/images/0019/001925/192525e.pdf.

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[pbuttigieg]

Def format cleanup from https://github.com/EnvironmentOntology/envo/issues/599#issuecomment-372256141

Source	Theme	Definition
NOAA Glossary of Hydrologic Terms	Snow	The process by which ice and snow dissipate owing to melting and evaporation.
NSIDC accessed 2016	Snow	(1) combined processes (such as sublimation, fusion or melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field; also used to express the quantity lost by these processes (2) reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches.
Cogley et al. IACS-UNESCO Glacier Mass Balance 2011	Snow	(1) All processes that reduce the mass of the glacier. (2) The mass lost by the operation of any of the processes of sense 1, expressed as a negative number. The main processes of ablation are melting and calving (or, when the glacier nourishes an ice shelf, ice discharge across the grounding line). On some glaciers sublimation, loss of windborne snow and avalanching are significant processes of ablation. 'Ablation', unqualified, is sometimes used as if it were a synonym of surface ablation, although internal ablation, basal ablation, and frontal ablation, especially calving, can all be significant in some contexts.
Molnia USGS 2004	Snow	Ablation refers to all processes by which snow, ice, or water in any form are lost from a glacier. Ablation is the loss of snow or ice by evaporation and melting. The rate at which ablation occurs depends on the atmospheric conditions present, such as air moisture content, solar radiation, temperature, and the reflectivity (Albedo) of the snow or ice surface. Fresh snow has a high albedo (0.7 to 0.9), indicating that 70 to 90 percent of the radiation received is reflected; glacier ice has a lower albedo of 0.2 to 0.4. Therefore, more radiation may be absorbed by glacier ice than by snow. Glaciers around the mountain receive different amounts of sunlight, so each glacier has its own characteristic ablation pattern.
Molnia USGS 2004	Snow	The loss of ice and snow from a glacier system. This occurs through a variety of processes including melting and runoff, sublimation, evaporation, calving, and wind transportation of snow out of a glacier basin.
Fierz et al. IACS-UNESCO Seasonal Snow on the Ground 2009	Snow	All processes that remove snow, ice, or water from a snowfield, glacier, etc., that is typically melt, evaporation, sublimation as well as wind erosion, avalanches, calving, etc.; in this sense, the opposite of accumulation. In many publications before 1980, ablation did not include mechanical removal of either snow or ice, i.e., wind erosion, avalanches, calving, etc.
NOAA National Weather Service Glossary 2009	Snow	Depletion of snow and ice by melting and evaporation.
WMO METEOTERM accessed 2016	Snow	(1) Combined processes (such as sublimation, melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field. Also used to express the quantity lost by these processes. (2) Reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches.
Environment and Climate Change Canada 2014	Snow	Reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches.
UNESCO-WMO International Glossary of Hydrology 2012	Snow	(1) Combined processes (such as melting, sublimation, evaporation or calving) which remove snow or ice from a glacier or from a snowfield; also used to express the quantity lost by these processes. (2) Reduction of the water equivalent of snow cover by melting, evaporation, wind and avalanches.
Swisseduc - Photo glossary of glaciological terms	Snow	The process of wastage of snow or ice by melting, sublimation and calving.
AMS - glossary of meteorology	Snow	1. All processes that remove snow, ice, or water from a glacier, snowfield, etc.; in this sense, the opposite of accumulation. These processes include melting, evaporation, calving, wind erosion, and an avalanche. Air temperature is the dominant factor in controlling ablation, precipitation amounts exercising only secondary control. During the ablation season (usually summer), an ablation rate of about 2 mm/h is typical of glaciers in a temperate climate. 2. The amount of snow or ice removed by the above-described processes; in this sense, the opposite of accumulation.
PhysicalGeography.net http://physicalgeography.net/	Snow	Surface removal of ice or snow from a glacier or snowfield by melting, sublimation, and/or calving.
Illustrated Glossary of Snow and Ice	Snow	All processes by which snow, ice, or water in any form are lost from a glacier, floating ice or snow cover. These include melting, evaporation, calving, wind erosion and avalanches. Also used to express the quantity lost by these processes.