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In meteorology, a cyclone is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above. Cyclones are characterized by inward-spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within the smaller mesoscale.
Numerical climate models are mathematical models that can simulate the interactions of important drivers of climate. These drivers are the atmosphere, oceans, land surface and ice. Scientists use climate models to study the dynamics of the climate system and to make projections of future climate and of climate change. Climate models can also be qualitative models and contain narratives, largely descriptive, of possible futures.
Mammatus is a cellular pattern of pouches hanging underneath the base of a cloud, typically a cumulonimbus raincloud, although they may be attached to other classes of parent clouds. The name mammatus is derived from the Latin mamma.
A funnel cloud is a funnel-shaped cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud but not reaching the ground or a water surface. A funnel cloud is usually visible as a cone-shaped or needle like protuberance from the main cloud base. Funnel clouds form most frequently in association with supercell thunderstorms, and are often, but not always, a visual precursor to tornadoes. Funnel clouds are visual phenomena, but these are not the vortex of wind itself.
Ensemble forecasting is a method used in or within numerical weather prediction. Instead of making a single forecast of the most likely weather, a set of forecasts is produced. This set of forecasts aims to give an indication of the range of possible future states of the atmosphere.
A hot tower is a tropical cumulonimbus cloud that reaches out of the lowest layer of the atmosphere, the troposphere, and into the stratosphere. These formations are called "hot" because of the large amount of latent heat released as water vapor that condenses into liquid and freezes into ice within the cloud. Hot towers in regions of sufficient vorticity may acquire rotating updrafts; these are known as vortical hot towers In some instances, hot towers appear to develop characteristics of a supercell, with deep and persistent rotation present in the updraft. The role of hot towers in tropical weather was first formulated by Joanne Simpson in 1958. Hot towers dominated discussions in tropical meteorology in the 1960s and are now considered the main drivers of rising air within tropical cyclones and a major component of the Hadley circulation. Although the prevalence of hot towers in scientific literature decreased in the 1970s, hot towers remain an active area of research. The presence of hot towers in tropical cyclones is correlated with an increase in the tropical cyclones' intensities.
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Tornadogenesis is the process by which a tornado forms. There are many types of tornadoes, varying in methods of formation. Despite ongoing scientific study and high-profile research projects such as VORTEX, tornadogenesis is a volatile process and the intricacies of many of the mechanisms of tornado formation are still poorly understood.
Horizontal convective rolls, also known as horizontal roll vortices or cloud streets, are long rolls of counter-rotating air that are oriented approximately parallel to the ground in the planetary boundary layer. Although horizontal convective rolls, also known as cloud streets, have been clearly seen in satellite photographs for the last 30 years, their development is poorly understood, due to a lack of observational data. From the ground, they appear as rows of cumulus or cumulus-type clouds aligned parallel to the low-level wind. Research has shown these eddies to be significant to the vertical transport of momentum, heat, moisture, and air pollutants within the boundary layer. Cloud streets are usually more or less straight; rarely, cloud streets assume paisley patterns when the wind driving the clouds encounters an obstacle. Those cloud formations are known as von Kármán vortex streets.
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In atmospheric science, a cold pool (CP) is a cold pocket of dense air that forms when rain evaporates during intense precipitation e.g. underneath a thunderstorm cloud or a precipitating shallow cloud. Typically, cold pools spread at 10 m/s and last 2–3 hours. Cold pools are ubiquitous both over land and ocean.
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References
- ↑ Speckman, Stephen (2001-07-24). "Utah a dust-devil haven". Deseret News. Retrieved 2021-10-11.
- ↑ Kanak, Katharine M.; Lilly, Douglas K.; Snow, John T. (October 2000). "The formation of vertical Vortices in the convective boundary layer". Quarterly Journal of the Royal Meteorological Society. 126 (569): 2789–2810. doi:10.1002/qj.49712656910. ISSN 0035-9009.
- ↑ Kanak, Katharine M. (2005-04-01). "Numerical simulation of dust devil-scale vortices". Quarterly Journal of the Royal Meteorological Society. 131 (607): 1271–1292. doi:10.1256/qj.03.172.
- ↑ Kanak, Katharine M. (October 2006). "On the numerical simulation of dust devil–like vortices in terrestrial and Martian convective boundary layers". Geophysical Research Letters. 33 (19). doi:10.1029/2006GL026207. ISSN 0094-8276.
- ↑ Cantor, Bruce A.; Kanak, Katharine M.; Edgett, Kenneth S. (December 2006). "Mars Orbiter Camera observations of Martian dust devils and their tracks (September 1997 to January 2006) and evaluation of theoretical vortex models". Journal of Geophysical Research: Planets. 111 (E12). doi:10.1029/2006JE002700. ISSN 0148-0227.
- ↑ Schultz, David M.; Kanak, Katharine M.; Straka, Jerry M.; Trapp, Robert J.; Gordon, Brent A.; Zrnić, Dusan S.; Bryan, George H.; Durant, Adam J.; Garrett, Timothy J.; Klein, Petra M.; Lilly, Douglas K. (2006-10-01). "The Mysteries of Mammatus Clouds: Observations and Formation Mechanisms". Journal of the Atmospheric Sciences. 63 (10): 2409–2435. doi:10.1175/JAS3758.1. ISSN 1520-0469.
- ↑ Kanak, Katharine M.; Straka, Jerry M.; Schultz, David M. (2008-05-01). "Numerical Simulation of Mammatus". Journal of the Atmospheric Sciences. 65 (5): 1606–1621. doi:10.1175/2007JAS2469.1. ISSN 1520-0469.
- ↑ Kanak, Katharine M.; Straka, Jerry M. (October 2009). "Effects of linear, ambient wind shear on simulated mammatus‐like clouds". Atmospheric Science Letters. 10 (4): 226–232. doi: 10.1002/asl.224 . ISSN 1530-261X.
- ↑ Straka, Jerry M.; Kanak, Katharine M.; Gilmore, Matthew S. (2007-08-01). "The Behavior of Number Concentration Tendencies for the Continuous Collection Growth Equation Using One- and Two-Moment Bulk Parameterization Schemes". Journal of Applied Meteorology and Climatology. 46 (8): 1264–1274. doi:10.1175/JAM2527.1. ISSN 1558-8432.
- ↑ Kanak, Katharine M. (Jun 2012). "Vitae". University of Oklahoma. Archived from the original on 2014-05-17. Retrieved 2014-05-17.
- ↑ "VORTEX2: Our Team". Archived from the original on 2016-08-01. Retrieved 2014-05-19.
