Kab rov tav arc kab rov tav ncig hauv av kuj tseem hu ua qhov tshwm sim ntawm kev thauj khoom txhua hnub lossis hnub ci thauj khoom. Kuj tseem muaj cov neeg hais ntawm cov huab zaj sawv thiab cov duab nag. Lub voj voos puag ncig yog hu ua qhov zoo nkauj tshaj plaws ntawm txhua qhov halo duab, thiab nws cov xim sib lawv liag txij toj mus rau hauv qab yog: liab, txiv kab ntxwv, daj, ntsuab, xiav, indigo, xiav-violet. Nws yog hom teeb ci.
Kab rov tav ib ncig ntawm lub qab ntug yuav tsuas pom thaum lub hnub tsawg kawg yog 58 qib ntawm lub qab ntug, tab sis nyob rau hauv nruab nrab-latitudes, lub hnub tsuas tuaj yeem mus txog qhov chaw siab no nyob rau lub Rau Hli thiab pib Lub Xya Hli, thiab tsuas yog hauv ob peb teev ua ntej thiab tom qab nruab nrab -Ib Sim.
Kev tsim cov txheej txheem ntawm circum-horizontal arc phenomenon zoo ib yam li ntawm qhov dhau los ntawm circum-zenith arc, thiab ob qho tib si los ntawm qhov cuam tshuam ntawm cov dej khov iav hauv cov huab cua sab saud irradiated los ntawm lub hnub ci. Qhov sib txawv yog tias qhov teeb meem teeb meem ntawm circum-horizontal arc phenomenon nkag los ntawm saum toj no cov dej khov siv lead ua, yog li cov xim txiav txim ntawm cov tsis sib haum xeeb yog rov qab rau qhov circum-zenith arc.