SWEET Ontology
type: Ontology
version info: 2.3
imports: matr.owl
imports: phen.owl
imports: matrWater.owl
imports: phenAtmoWindMesoscale.owl
imports: phenAtmo.owl
imports: relaSpace.owl
imports: relaChemical.owl
imports: rela.owl
imports: state.owl
imports: matrAerosol.owl
imports: procPhysical.owl
imports: phenMixing.owl
imports: phenFluidInstability.owl
imports: phenFluidTransport.owl
imports: phenAtmoPressure.owl
imports: realmLandOrographic.owl

Anvil Cloud
type: Class
subclass of: Cloud
subclass of: Restriction
  on property: upperPartOf
  all values from: Cumulonimbus
comment: The anvil-shaped cloud that comprises the upper portion of mature cumulonimbus clouds
comment: a type of cloud

BannerCloud
type: Class
subclass of: Cloud
comment: A cloud plume often observed to extend downwind from isolated, sharp, often pyramid-shaped mountain peaks, even on otherwise cloud-free days.

BaroclinicLeaf
type: Class
subclass of: Restriction
  on property: hasPhenomena
  all values from: Cyclogenesis
subclass of: Cloud
comment: A synoptic-scale cloud pattern frequently observed in satellite imagery just prior to the onset of cyclogenesis

BillowCloud
type: Class
subclass of: Cloud
comment: A cloud variety composed of merged or separate elements that are elongated and parallel, either suggestive of ocean waves or arranged in ranks and files.

Cloud
type: Class
subclass of: MeteorologicalPhenomena
subclass of: Restriction
  on property: hasSubstance
  some values from: CloudCondensationNuclei
subclass of: Restriction
  on property: hasSubstance
  some values from: Ice
comment: A visible aggregate of minute water droplets and/or ice particles in the atmosphere above the earth's surface.

Cumulonimbus
type: Class
subclass of: Cloud
comment: A principal cloud type (cloud genus), exceptionally dense and vertically developed, occurring either as isolated clouds or as a line or wall of clouds with separated upper portions.

Cumulus
type: Class
subclass of: Restriction
  on property: hasPhenomena
  all values from: Convection
subclass of: Cloud
comment: A principal cloud type (cloud genus) in the form of individual, detached elements that are generally dense and posses sharp nonfibrous outlines.

FoehnCloud
type: Class
subclass of: Cloud
subclass of: Restriction
  on property: hasPhenomena
  all values from: Foehn
comment: Any cloudform associated with the foehn, usually referring to standing clouds of two types, orographic clouds and mountain wave clouds. Orographic clouds may include crest clouds and the foehn wall. Wave clouds may consist of lenticular (including altocumulus standing lenticular, or ACSL) clouds, lee-wave clouds and cloud bands, and rotors. See also Bishop wave, chinook arch, contessa di vento, Moazagotl.

FoehnWall
type: Class
equivalent class: FoehnCloud
comment: The leeward edge of the orographic stratiform cap cloud as seen from the lee side of a mountain barrier, preceding or during a foehn or chinook event. The edge is generally abrupt and resembles a wall of cloud (?foehnwand? in German). This cloud often signifies the occurrence of orographic precipitation, especially snowfall in the cold season, over the peaks. See foehn cloud.

ForcedCloud
type: Class
subclass of: Cumulus
comment: Small cumulus clouds that are everywhere negatively buoyant compared to the surrounding environment, but that exist because the inertia of the rising thermals feeding them from underneath is sufficient to penetrate the lifting condensation level (LCL). Morphologically, these are often cumulus humilis clouds and are typically found at the top of the convective boundary layer during daytime over land, when a strong temperature inversion aloft prevents the clouds from growing deeper. Compare active cloud, passive cloud.

FunnelCloud
type: Class
subclass of: Cloud
subclass of: Restriction
  all values from: Rotation
  on property: hasProcess
comment: A condensation cloud, typically funnel-shaped and extending outward from a cumuliform cloud, associated with a rotating column of air (a vortex) that may or may not be in contact with the ground. If the rotation is violent and in contact with the ground, the vortex is a tornado. Funnel clouds can occur through a variety of processes in association with convection. For example, small funnel clouds are infrequently seen extending from small, dissipating cumulus clouds in environments with significant vertical wind shear in the cloud-bearing layer.

KelvinHelmholtzBillows
type: Class
subclass of: Restriction
  on property: hasState
  all values from: KelvinHelmholtzInstability
subclass of: Cloud
comment: 1. Cloud forms that arise from Kelvin?Helmholtz waves. 2. Vortical structures that result from the growth and nonlinear development of unstable waves in a shear flow. The billows get their name from the instability responsible for the growth of the unstable waves, Kelvin?Helmholtz instability.

LayerCloud
type: Class
subclass of: Restriction
  on property: hasPhenomena
  all values from: CappingInversion
subclass of: Cloud
comment: Stratus cloud; a continuous cloud sheet capped by an inversion.

LenticularCloud
type: Class
subclass of: Cloud
comment: A commonly used term for clouds of the species lenticularis.

Mamma
type: Class
subclass of: Cloud
comment: (Also called mammatus.) Hanging protuberances, like pouches, on the undersurface of a cloud. This supplementary cloud feature occurs mostly with cirrus, cirrocumulus, altocumulus, altostratus, stratocumulus, and cumulonimbus; in the case of cumulonimbus, mamma generally appear on the underside of the anvil (incus). See cloud classification.

MaritimeCloud
type: Class
subclass of: Cloud
comment: A cloud forming in maritime air containing relatively low concentrations of cloud condensation nuclei. These clouds are characterized by a broader droplet size distribution and low droplet concentrations (some 100 cm-3). See continental cloud.

MixedCloud
type: Class
subclass of: Cloud
comment: A cloud containing both water drops (supercooled at temperatures below 0?C) and ice crystals, hence a cloud with a composition between that of a water cloud and that of an ice- crystal cloud.

MixingCloud
type: Class
subclass of: Cloud
subclass of: Restriction
  on property: hasPhenomena
  some values from: Mixing
comment: A cloud formed when two subsaturated volumes of moist air with different temperatures and vapor pressures mix isobarically and adiabatically to form a volume of moist air with an intermediate temperature and vapor pressure above the saturation value at that temperature.

MountainWaveCloud
type: Class
subclass of: Restriction
  on property: hasPhenomena
  all values from: MountainWave
subclass of: Cloud
comment: A cloud that forms in the rising branches of mountain waves and occupies the crests of the waves. The most distinctive are the sharp-edged, lens-, or almond-shaped lenticular clouds, but a variety of stratocumulus, altocumulus, and cirrocumulus forms appear in both the main, vertically propagating waves and in the lee waves. See mountain wave, foehn cloud.

Nimbostratus
type: Class
subclass of: Cloud
comment: A principal cloud type (cloud genus), gray colored and often dark, rendered diffuse by more or less continuously falling rain, snow, sleet, etc., of the ordinary varieties and not accompanied by lightning, thunder, or hail.

NoctilueentCloud
type: Class
subclass of: Cloud
comment: (Rarely called luminous clouds.) Thin silvery-blue cirrus-like clouds frequently seen during summer twilight conditions at high latitudes (above 50?) in both hemispheres. They are the highest visible clouds in the atmosphere, occurring in the upper mesosphere at heights of about 85 km, and are closely related to the polar mesospheric clouds seen in satellite observations at similar altitudes over the summer polar cap. Noctilucent clouds are now known to consist of tiny ice particles with dimensions of the order of tens of nanometers, growing in the extreme cold of the summer polar mesopause region. The condensation nuclei on which the particles grow are thought to be either smoke and dust particles of meteoric origin or large hydrated positive ions. Strong upwelling of air from below, associated with a pole-to-pole meridional circulation in the upper mesosphere, is responsible for both the extreme cold and the upward flux of water vapor. Although water-vapor mixing ratios are very low (less than 10 parts per million by volume) in the region, the temperatures are also low enough to produce a high degree of supersaturation at times. Anomalously strong radar echoes from the region, known as polar summer mesospheric echoes, are also associated with the clouds. Compare nacreous clouds, polar stratospheric clouds.

OrographicCloud
type: Class
subclass of: Cloud
subclass of: Restriction
  on property: hasPhenomena
  all values from: Orographic
comment: Mountain clouds produced by orographic lifting of moist air to saturation.

OvershootingTop
type: Class
subclass of: Cloud
subclass of: Restriction
  on property: upperPartOf
  all values from: Anvil Cloud
comment: A domelike protrusion above a cumulonimbus anvil, representing the intrusion of an updraft through its equilibrium level.

PassiveCloud
type: Class
subclass of: Cumulus
comment: A cumulus cloud that is no longer dynamically connected with the atmospheric boundary layer via updrafts or downdrafts.

RollCloud
type: Class
subclass of: Cloud
comment: A low-level, horizontal, tube-shaped arcus cloud associated with a gust front of a convective storm or occasionally a cold front.

SelfCloud
type: Class
subclass of: Cloud
comment: A low-level, horizontal, wedge-shaped arcus cloud associated with a convective storm's gust front.

Altostratus
type: Class
subclass of: Stratiform
comment: A principal cloud type (cloud genus) in the form of a gray or bluish (never white) sheet or layer of striated, fibrous, or uniform appearance.

WallCloud
type: Class
subclass of: Cloud
comment: A local, often abrupt lowering from a cumulonimbus cloud base into a low-hanging accessory cloud, normally a kilometer or more in diameter.

BlackShearedAnvil
type: Class
subclass of: Cumulonimbus
comment: Colloquial expression for a cumulonimbus anvil that spreads upwind into relatively strong winds aloft.

LaSerpe
type: Class
subclass of: Cloud
comment: A long strip of cloud that sometimes lies against the southern base of Mount Etna in Sicily. It is said to herald rain.

Moazagotl
type: Class
equivalent class: FoehnCloud
subclass of: LenticularCloud
comment: A stationary bank of cirriform cloud marking the upper portion of the system of lenticular clouds formed in the lee wave produced by flow across the Sudeten Mountains in southeastern Germany; a type of foehn cloud.

FlankingLine
type: Class
subclass of: MeteorologicalPhenomena
subclass of: Restriction
  on property: hasPhenomena
  all values from: Cumulonimbus
subclass of: Restriction
  on property: hasPhenomena
  all values from: Cumulus
comment: An organized lifting zone of cumulus and towering cumulus clouds, connected to and extending outward from the mature updraft tower of a supercell or strong multicell convective storm.