Abr

ABR, mahsuli muallaqi kondensatsiyai bugi ob dar atmosfera, ki dar osmon az sathi zamin mushohida meshavad. Abr az qatrahoi khurdtarini ob yo zarrahoi yakh iborat ast. Abr omili muhimi obu havost, ki nizomi borishoti atmosferiro muayyan me¬kunad va ba mizoni harorati atmos¬fera tasir merasonad. Abr ba hisobi miyona qarib nimi gunbazi osmonro mepushad va to 109t ob dorad. Bugi ob asosan dar qismi poyoni atmosfera – troposfera voqe megardad.

Binobar in beshtarini abrho dar balandihoi gunoguni on paydo meshavand. Har goh ki havoi nam sard shuda, ba kharorati bugi ser, yane to nuqtai hosil gardidani shabnam rasid, Abr paydo meshavad. Khunukshavii havo ba tufayli vaseshavii adiabati hangomi harakati amudii on ba amal meoyad, ki in natijai konveksiyai termiki va dinamikist. Hangomi ba seri rasidani bugi ob dar natijai kondensatsiya dar sathi zarrahoi khurdi gigroskopi: chang, gubor, mahsuli dud va gayra, ki yadroi kondensatsiyaand, qatrahoi nav paydo meshavand.

Saravval qatrachahoi Abr az hisobi kon- densatsiyai bugi ob meafzoyand; minbad qatraho ba yakdigar barkhurda yakjoya meshavand, yane koagulyatsiyai elementhoi Abr ba amal meoyad. Ba tufayli koagulyatsiya qatrachahoi Abr to ba andozai qatrahoi boron merasand va dar sharoiti muayyan az Abr ba shakli borishot furud meoyand. Dar hududi kharorathoi manfi Abr az qatrachahoi ob, zarrahoi yakh yo omekhtai onho tarkib yofta metavonad.

Abrho az rui namudi zohiri va balandii asosi khud az yakdigar farq mekunand. Darajai bo Abr pushida shudani gunbazi osmon bo mafkhumi abrnoki ifoda meyobad. Abrnokiro az rui shkalai dahballa va shakli onro az rui tasnifoti baynalkhalqi muayyan mekunand. Balli osmoni beabr ba sifr va osmoni purra abrpush ba 10 barobar ast.

Balandii abrhoro vizuali (bo did) yo bo yorii kurzondho muayyan kardan mumkin ast. Shaklhoi asosii Abr: Abrehoi tabaqai bolo (balandii asosashon ziyoda az 6 kilometr), ki abrhoi parshakl, parshakli serqabat, parshakli tudaro dar megirand; Abrhoi tabaqai mobayn (balandii asosashon 2-6 kilometr), ki az Abrhoi serqabati baland, tudaabri baland iboratand; Abrhoi tabaqai poyon (balandii asosashon kamtar az 2 kilometr), ki doroi Abrhoi serqabat, serqabati tuda, serqabati boroni me- boshand. Abrhoe niz mavjudand, ki amudvor tashakkul va inkishof meyoband. Asosi onho dar balandii 1 – 1,5 kilometr voqe gardida, balandii qullaashon to 10 kilometr va ziyodtar merasad. Tudaabr va tudaabri boroni az hamin qabiland.

Asosi tudaabrho nisbatan hamvor va qullahoyashon gunbazshakl meshavad va hajman vusat yofta, ba tudaabri boroni (abrhoi radubarqi, tundari) tabdil meyoband. Ba jarayoni abrhosilshavi khususiyathoi geografi tasir msrasonand. Dar Tochikiston mavjudiyati kuhho, gunogunii relyef va iqlim sababi paydoishi abrhoi mahalli megardand. Dar nohiyahoi kuhi, asosan dar boloi kuhho, tuda- abrho inkishof meyoband, zero dar nishebihoi oftobruya havo garm shuda, bolo meravad va boisi paydo¬ishi abrho megardad. Abrhoe, ki dar boloi qatorkuhho paydo meshavand va sokin meistand, «abrbayrak» nom giriftaand. Dar vodihoi balandkuh bazan shakli ajibi Abr- «tumani kuhi»-ro mushohida kardan mumkin.

Dar Pomir az sababi kam budani na¬mii havo tudaabrho dar balandihoi 6 – 6,5 kilometr paydo meshavand. Dar vodihoi Tochikiston ruzhoi abrnok kam buda (sole 30 – 40 ruz), bo ziyod shuda¬ni balandii mahal meafzoyand, dar agbayu piryakhho ruzhoi abrnok beshtar (masalan, dar agbai Anzob 100 va mintaqahoi balandkuhi yakhbasta to 150 ruz va ziyodtar) megardand. Odatan, dar ayyomi khunuki sol asosan pay¬doishi abrhoi serqabat va dar ayyomi garmi sol tudaabrho va tudaabrhoi boroni (makhsusan dar mohi may) khos ast. Az abrhoi radubarqi boroni sel va beshtar jola meborad, ki ba kishovarzi zarar merasonad.

Abr gayr az Zamin dar hamai sayyorahoi atmosferaashon gazi, inchunin Mirrikh, Zuhra, radifoni Zuhal – Titan va Neptun – Triton mushohida meshavad. Abrhoi gayrizamini tabiati gunogun dorand. Masalan, dar Zuhra qabathoi Abr az kislotai sulfat iborat buda, dar Titan manbai boronhoi metani dar harorati -180° meboshand.
V. Perchechko, M. Kholov.