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Cirrus

Cirrus may refer to a variety of topics in different fields. In science, it denotes cirrus clouds, a of high-altitude ice-crystal clouds, or cirrus in , referring to thin, thread-like structures on animals. In aviation, it includes , a manufacturer of planes, and Cirrus aero engines, a series of historical British engines. In music, Cirrus is the name of an electronic music band as well as various songs and . Other uses encompass companies named Cirrus and miscellaneous applications.

Science

Clouds

Cirrus clouds are a of high-altitude clouds occurring above 6 (20,000 ), primarily composed of crystals that give them a delicate, fibrous, or feathery appearance as white filaments, patches, or narrow bands. They form part of the World Meteorological Organization's (WMO) international cloud classification system, denoted by the symbol , and belong to the high cloud family alongside cirrostratus and cirrocumulus. These clouds develop exclusively in cold upper tropospheric environments where temperatures drop below -20°C, preventing the presence of supercooled liquid water. The formation of cirrus clouds arises through several processes, including high-altitude that lifts moist air, anvil blow-off from the tops of cumulonimbus clouds during deep , or nucleation in supersaturated air masses at temperatures below -40°C. In these conditions, water vapor deposits directly onto ice nuclei—such as or particles—via heterogeneous , or homogeneously freezes without nuclei at relative humidities exceeding 140% with respect to , bypassing any liquid phase. This results in sparse crystal concentrations, typically ranging from 5 to 500 per liter, which contribute to the clouds' thin structure. Physically, cirrus occupy altitudes of 5–13 in temperate regions, with tops reaching up to 14 in the and bases ranging from 3 in polar areas to higher altitudes elsewhere; their translucent allows most sunlight to penetrate while scattering minimally, often producing optical phenomena such as halos, sundogs, and coronas through by the crystals. crystals within cirrus vary in , including hexagonal plates, columns, and aggregates, with sizes generally increasing downward from about 50 μm near the top to over 1 mm at the base. Cirrus clouds exhibit several distinct species as defined by the WMO, including fibratus (straight, hair-like filaments), uncinus (hooked or comma-shaped with trailing ), castellanus (with turreted or cumuliform protuberances indicating local ), floccus (small, fluffy tufts often with dangling ), and spissatus (dense, opaque patches that may obscure or ). These can combine with other high-cloud genera to form cirrocumulus (patchy, rippled layers) or cirrostratus (widespread veils). In terms of meteorological significance, cirrus serve as indicators of upper-level moisture, , and approaching systems, such as warm fronts, often appearing 12–24 hours in advance of . Climatically, they play a key role by trapping outgoing longwave —contributing to a net warming effect of approximately +5.7 W m⁻² globally—while reflecting only a small fraction of incoming shortwave solar due to their low (typically 0.1–5). This enhancement outweighs their cooling, making cirrus a in models, though their exact impact varies with thickness and location. The study of cirrus clouds traces back to their formal naming by British meteorologist Luke Howard in his 1803 essay "On the Modifications of Clouds," where he classified them as one of the three primary cloud types alongside cumulus and stratus. Modern observations rely on techniques, including satellite instruments like MODIS on NASA's and Aqua platforms, which retrieve ice water content, optical depth, and effective crystal sizes using multispectral channels (e.g., 1.64 μm and 3.75 μm) to infer vertical profiles. Ground-based and spaceborne systems, such as those on , further characterize size distributions—typically ranging from 10 to 1000 μm—by analyzing backscattered light from non-spherical particles, aiding in the validation of microphysical models and estimates.

Biology

In biology, a cirrus (plural: cirri) refers to a long, slender, thread-like projection or in various , typically flexible and lacking the muscular strength or thickness of tentacles. Derived from the Latin cirrus meaning "" or "," the term evokes the wispy, curled appearance analogous to cirrus clouds. These structures are often lightweight adaptations suited to low-energy roles in or humid environments, emphasizing over robustness. Cirri are particularly prominent in , where they support essential survival functions. In annelids, such as the ragworm (now classified as ), cirri form paired appendages on the parapodia of each body segment, aiding locomotion by propelling the worm through water or burrows, enhancing respiration via increased surface area for oxygen uptake, and facilitating feeding by stirring sediment or water to draw in particles. In of the subclass Cirripedia, cirri manifest as feathery, multi-jointed thoracic legs that extend from the protective shell plates; these actively beat to generate currents, enabling filter-feeding on and suspended organic matter in otherwise sessile adults. Examples extend to vertebrates, , and microscopic taxa. Certain fish, including gobies (family ), bear oral or nasal cirri—fleshy filaments around the mouth—that serve sensory functions, such as tactile detection of prey or substrates, and in cleaner gobies, assist in parasite removal from host fish during mutualistic interactions. In , cirri appear as coiling tendrils in climbing vines like Passiflora species (), which thigmonastically respond to touch by wrapping around supports, securing the vine's upward growth toward sunlight and reducing structural investment in the stem. At the microscopic level, in ciliate protozoans such as hypotrichs (e.g., ), cirri are fused bundles of cilia forming leg-like tufts for coordinated "walking" or jumping across substrates, distinct from free-swimming cilia. In fungi, cirri (or cirrhi) are viscous, coiled masses of spores extruded from pycnidia or perithecia in ascomycetes, facilitating dispersal via rain splash or wind in moist conditions. Across taxa, cirri primarily enable sensory detection via mechanoreceptors for tactile cues, feeding through current generation or particle capture, locomotion in fluid media, and attachment for stability or climbing; these reflect convergent evolutionary solutions, especially in habitats, favoring flexible, energy-efficient designs over rigid forms. highlights cirral morphology's taxonomic value, with variations in cirri number, segmentation, and arrangement distinguishing in groups like polychaetes and —key for assessments in coral-associated or benthic faunas. Ecologically, cirri-bearing organisms drive nutrient cycling and community dynamics in seafloor ecosystems, as their feeding and burrowing activities aerate sediments and redistribute .

Aviation

Aircraft

Cirrus Aircraft, founded in 1984 by brothers Alan and Dale Klapmeier in a family barn in , emerged as a pioneer in by focusing on innovative, user-friendly personal aircraft constructed primarily from composite materials. The company relocated to , in 1994 to accommodate growing demand, where it established its headquarters and primary manufacturing operations. Originally known as Cirrus Design Corporation, it rebranded to following its 2011 acquisition by (CAIGA), a subsidiary of the state-owned ; despite the ownership change, Cirrus has maintained its U.S.-based design, production, and executive functions in Duluth to ensure operational independence and compliance with American standards. This structure has allowed Cirrus to emphasize safety-oriented, high-performance aircraft tailored for owner-pilots, blending advanced technology with luxury features to democratize personal flight. The company's early milestone came with the VK-30, a composite plane whose achieved its first flight in 1988, marking Cirrus's entry into and leading to initial deliveries that year. Building on this foundation, Cirrus transitioned to certified production models, securing (FAA) type certification for the SR20 piston single in October 1998, with the first customer delivery in July 1999. The SR22 followed in November 2000, introducing enhanced performance and becoming the world's best-selling by 2002. In a bold expansion into jet , the Vision SF50—marketed as the Vision Jet—made its in 2008 and received FAA certification on October 28, 2016, as the first single-engine approved for personal civilian use, with initial deliveries commencing that December. These developments were complemented by service expansions, including the launch of Cirrus Pilot Training programs in the early to support new owner-pilots and management services to facilitate ownership logistics. Central to Cirrus's reputation are its key innovations prioritizing safety and pilot ease. The (CAPS), introduced as standard equipment in 1995, was the first whole-airframe deployed via rocket for recovery, dramatically reducing fatal accident rates by enabling safe descents from altitudes as low as 500 feet. As of November 2025, the CAPS system had recorded 141 successful deployments, saving 285 lives, including recent events such as midair collisions and structural failures. Complementing this, Cirrus pioneered glass cockpits in the late 1990s and integrated the advanced Perspective avionics suite starting in 2008, featuring intuitive touchscreen interfaces, synthetic vision, and automated flight management to minimize pilot workload and enhance . These features, combined with ergonomic seating, climate control, and optional luxury upgrades like leather interiors, position as accessible yet premium options for non-professional pilots, though operators must remain vigilant for challenges such as reduced visibility in high-altitude layers during cruise. The SR Series—encompassing the four-seat SR20 for training and entry-level flying, and the faster six-seat SR22 and turbocharged SR22T for cross-country travel—forms the core of Cirrus's piston-engine lineup, with over 10,000 units delivered by mid-2024 alone. The Vision Jet, a five-to-seven-seat model with a , represents a disruptive entry into personal , boasting over 600 deliveries by the end of 2024 and features like a unique circular "Safe Return" emergency system certified in 2020. By October 2025, Vision Jet deliveries exceeded 700, contributing to ongoing production growth. By 2025, cumulative production across all lines exceeded 10,500 aircraft, underscoring Cirrus's scale in the light aircraft segment. Cirrus dominates the U.S. market, capturing nearly 50% unit share for its Series in 2025 through a combination of innovative records and efficient , while contributing economically via jobs, partnerships, and exports to over 60 countries. The CAPS system's proven impact has not only bolstered consumer confidence but also influenced industry-wide standards, with Cirrus's overall fatal accident rate remaining below the general aviation average. As of 2025, Cirrus employs approximately 2,750 people across its U.S. facilities, supporting robust production amid growing demand. The company continues facility expansions, including a $13 million addition of 30,000 square feet to its , composite manufacturing site announced in June 2025, aimed at increasing output for both SR Series and Vision Jet components. Ongoing efforts focus on enhancing integration and sustainability features, building on Cirrus's legacy of transforming personal .

Engines

The Cirrus engines originated in the mid-1920s as a series of air-cooled, inline-four-cylinder aero engines designed by Major Frank Halford, who drew on surplus V8 components to create a reliable powerplant for , including early models. Halford's design emphasized simplicity and cooling efficiency, marking the first upright air-cooled inline-four to achieve type in 1925 with the 90 hp Cirrus I model. Initial production occurred under the Aircraft Disposal Company (), transitioning to Cirrus Aero Engines Ltd. in 1927, then to the Cirrus-Hermes Engineering Co. in 1931, before acquired the rights in 1937 and continued manufacturing the range. Blackburn's involvement extended production into the late 1950s, focusing on inverted configurations for improved pilot visibility in . Key historical models included the four-cylinder Cirrus Minor II, introduced around 1929, which produced 60 hp at 2,000 rpm with a displacement of 4.5 liters, a bore of 105 mm, stroke of 130 mm, and compression ratio of 5:1, achieving fuel consumption rates of approximately 4.5-5 gallons per hour at cruise settings. The Cirrus Major series, developed in the 1930s, offered higher output in inverted layouts; for instance, the Major III variant delivered 150 hp at 2,450 rpm from a 6.32-liter displacement, with a bore of 120 mm, stroke of 140 mm, and compression ratio of 6.5:1, while maintaining similar fuel efficiency through carbureted induction and dry-sump lubrication. These engines weighed around 280-300 pounds dry, prioritizing lightweight construction for small airframes without sacrificing durability. Although early plans explored six-cylinder variants for greater power, production focused on refined four-cylinder designs. Design features of the historical Cirrus engines centered on air-cooling via finned cylinders and baffled airflow, paired with wooden fixed-pitch propellers and mechanical carburetion for straightforward operation in open-cockpit trainers. Reliability was enhanced through robust crankshafts and sodium-cooled exhaust valves in later models, contributing to low maintenance needs in pre-war aviation. Although bespoke production waned post-World War II, the engines' legacy influenced light aircraft propulsion, powering early British racers and trainers like the and contributing to the evolution of post-war designs. In contemporary applications, integrates third-party engines under certified Cirrus-branded packages, emphasizing reliability and fuel efficiency tailored to composite airframes; for example, the SR20 uses a 200 IO-360-ES four-cylinder , while the SR22 employs a 310 IO-550-N six-cylinder variant, enabling cruise speeds of 155-183 knots. The Vision Jet features a Williams FJ33-5A with 1,846 pounds of , mounted pylon-style for reduced noise and optimized integration, achieving up to 300 knots in cruise. Modern setups incorporate electronic ignition and, for the jet, to automate fuel metering and management, improving by 10-15% over systems. By the 1940s, Cirrus shifted from standalone development to partnerships with manufacturers like and Lycoming for engines, discontinuing new bespoke designs after the as market demands favored standardized powerplants. This evolution allowed Cirrus branding to persist in specifications, supporting high-performance light without proprietary engine production.

Music

Band

Cirrus is an American electronic music duo formed in 1995 in , , by DJ and bassist Aaron , a classically trained , and multi-instrumentalist Stephen Barry, a and . The pair, later joined by Jim Chaney for live performances, gained prominence in the mid-1990s and scenes through their high-energy live sets blending electronic production with organic instrumentation. Active primarily through the late 1990s and early 2000s, the group continued relevance via remastered releases into the 2020s. The duo's musical style fused , , , and , drawing influences from contemporaries like and , as well as , with whom they were compared by their label in 1997. Their sound was defined by pulsating heavy basslines, chopped and sampled , futuristic synth leads, and acid-tinged elements, creating an energetic, dancefloor-oriented aesthetic suited to the era's underground electronic culture. This take on helped distinguish them in a scene dominated by acts, emphasizing live alongside programmed beats for a rock-infused edge. Key releases include their debut album Drop the Break (1997) on Moonshine Music, featuring singles such as "Back to the " and "Cirrus," which captured their raw, rave-ready energy. Follow-up albums Back on a Mission (1998), Stop & Panic (1999), and (2002) expanded their palette, incorporating more and pop elements while maintaining high-BPM breaks. Tracks from these works appeared on various compilations, amplifying their reach. Career highlights encompassed national tours supporting major electronic acts, including performances alongside DJs in the burgeoning U.S. rave circuit, and remixes for artists like Paul van Dyk ("Nothing But You") and DJ Keoki ("Majick"). Their contributions extended to the late-1990s rave scene, where they helped popularize breakbeat and big beat on the West Coast through club residencies and festival appearances. The group ceased regular activity around 2002 following the release of Counterfeit, though their catalog endured in DJ sets and mixes. Cirrus's legacy lies in pioneering a distinctive big beat sound that bridged electronic and rock elements, influencing subsequent producers and remaining a staple in compilations. By 2025, their music is widely available on streaming platforms like and , bolstered by remastered editions such as the 25th-anniversary deluxe version of Drop the Break (2023), ensuring ongoing accessibility for new generations.

Songs and albums

The electronic music duo Cirrus, known for their and productions, released several notable during their active years in the late and early 2000s. Their 1998 Back on a Mission, featuring high-energy tracks like the title song, captured the dancefloor vibe of the era with pulsating rhythms and synth-driven hooks, contributing to the group's reputation in the electronic scene. Other releases, such as the 1997 Drop the Break and the 1999 Stop & Panic, showcased their blend of acid breaks and club-oriented beats, emphasizing atmospheric movement through layered instrumentation. Among songs titled "Cirrus," Bonobo's 2013 track from the album The North Borders stands out as an ambient electronica piece incorporating orchestral elements and ethereal synths, evoking the wispy, high-altitude nature of cirrus clouds. The song, part of an album that blended downtempo grooves with live instrumentation, received positive critical attention for its immersive soundscape, though reviewers noted its polished, inoffensive quality. Similarly, Pink Floyd's "Cirrus Minor," the opening track on their 1969 soundtrack album More, is a psychedelic folk composition with dreamlike lyrics about natural imagery and a backdrop of chirping birds and organ swells, creating bird-like auditory effects that enhance its hazy, atmospheric theme. Cirrus's works were praised for their infectious dance energy, aligning with the movement's emphasis on high-BPM grooves suitable for club environments. Bonobo's "Cirrus" has seen significant cultural reach, appearing in various media placements and accumulating substantial streaming plays, underscoring its enduring appeal in electronic music.

Other uses

Companies

, Inc. is a fabless company founded in 1984 and headquartered in , specializing in low-power, high-precision analog, mixed-signal, and audio integrated circuits for consumer electronics, particularly audio and applications in smartphones and tablets. The company supplies digital-to-analog converters and other audio components to major device manufacturers, including Apple, where its chips have been integrated into iPhones since the early to enable high-fidelity audio playback and recognition features. In fiscal year 2024 (ended March 2024), reported revenue of $1.79 billion, driven primarily by demand from flagship mobile devices, though it faced headwinds from disruptions following the that constrained component availability and impacted production. Key milestones for Cirrus Logic include its on the in June 1989 under the ticker CRUS, which provided capital for early expansion into mixed-signal processing. Jason Rhode served as CEO from 2007 to , overseeing a shift toward audio-centric products and strategic acquisitions such as Apex Microtechnology in 2007, which bolstered its high-voltage analog portfolio for industrial and medical applications before being divested in 2014. John Forsyth succeeded Rhode as CEO in January 2021, leading recent innovations in low-power audio solutions that enhance battery life in wearables and enable features like always-on voice activation. The company's contributions to low-power audio technology have extended to sectors like consumer audio devices, where its codecs support and high-efficiency amplification, though specific applications in hearing aids remain limited to general mixed-signal components rather than proprietary halo technologies. Cirrus Aircraft, founded in 1984 and based in Duluth, Minnesota, is a leading manufacturer of personal and light business aircraft, operating as a subsidiary of China Aviation Industry General Aircraft Co. (CAIGA) since a 2011 merger that facilitated global expansion. The company maintains a worldwide sales and service network, with over 100 authorized centers across North America, Europe, Asia, and Australia, supporting deliveries of its piston and jet models to international customers. In 2025, Cirrus Aircraft pursued growth initiatives including a facility expansion in Grand Forks, North Dakota, to increase production capacity, and enhanced training infrastructure such as a new Vision Jet simulator in Scottsdale, Arizona, amid rising demand in emerging markets. Its partnership with CAIGA has enabled joint ventures in Asia, including localized manufacturing and sales support, contributing to half-year revenue of $594 million as of June 2025. Cirrus Identity, Inc., founded in 2013 and headquartered in , develops cloud-based software tailored for , research institutions, and enterprises. The company's platform simplifies secure , guest access, and services, integrating with systems like to streamline user and compliance with standards such as InCommon. It serves clients in the academic sector by addressing challenges in multi-institutional data sharing and privacy, with a focus on scalable, low-maintenance solutions for IT teams. Historically, Cirrus Aero Engines Ltd. was a British firm established in 1927 in Coventry to produce the Cirrus series of inline aero engines, which powered early light aircraft like the de Havilland DH.60 Moth during the interwar period. The company originated from designs by the Aircraft Disposal Company (ADC) in the mid-1920s and underwent reorganization in 1931 as Cirrus-Hermes Engines Ltd., continuing production of four-cylinder engines up to 120 horsepower until the late 1930s, after which operations wound down without direct merger into larger entities like Bristol Aero Engines.

Miscellaneous

In software development, CirrusSearch is an open-source extension that provides advanced search capabilities using as its backend, later migrated to for enhanced performance and scalability. Developed by the , it supports features like , relevance ranking, and integration with PoolCounter to manage concurrent queries efficiently, powering search on platforms such as . Released publicly under an , it enables wikis to handle large-scale indexing and querying of content. In fiction and media, "cirrus" appears as a procedural cloud type in the video game No Man's Sky, where the game's universe generation system includes wispy cirrus clouds as part of its rewritten volumetric cloud rendering introduced in the Worlds Part I update. These high-altitude, ice-crystal-like formations contribute to the procedural atmospheres on procedurally generated planets, enhancing visual variety and realism in the game's exploration mechanics.