Ke kumu o ka uliuli o ka lani
He mea maʻamau ka lani polū i kēlā me kēia lā a mākou e manaʻo pinepine ai he mea maʻamau. Eia nō naʻe, ma hope o kēia lani polū nani kahi hanana kino hoihoi a paʻakikī hoʻi. No ke aha he polū ka lani? I mea e maopopo ai kēia hanana, pono mākou e ʻeli hohonu i nā manaʻo kumu o ka physics lewa, ka hoʻopuehu ʻana o ka mālamalama, a me ka pilina ma waena o ka lā a me ka lewa o ko mākou Honua.
Ka Lā a me ke Kikowaena Waihoʻoluʻu
Ke ʻike ʻia nei ke kukui o ka lā he keʻokeʻo i ko mākou mau maka, akā ua haku ʻia ʻo ia me nā kala he nui i ʻike ʻia ma ke ʻano kukui. Aia kēia ʻano kukui i nā kala o ke ānuenue: ʻulaʻula, ʻalani, melemele, ʻōmaʻomaʻo, uliuli, indigo, a me ka poni. He ʻokoʻa ka nalu o kēlā me kēia kala i loko o ke ʻano kukui, mai kahi o 700 nanometers no ka ʻulaʻula a i kahi o 400 nanometers no ka poni.
Ke komo ka lā i ka lewa o ka Honua, launa pū ia me nā molekala liʻiliʻi a me nā ʻāpana i ka lewa. ʻO kēia hanana ke kumu e loli ai ke kala o ka lewa ma muli o ka manawa o ka lā a me nā kūlana. ʻO ka hoʻopuehu ʻana o Rayleigh ke kī i ka hoʻomaopopo ʻana i ke kumu e ʻike pinepine ʻia ai ka lani he uliuli.
Ka hoʻopuehu ʻana o Rayleigh
ʻO ka hoʻopuehu ʻana o Rayleigh ka hanana o ka hoʻopuehu ʻana o ka mālamalama e nā ʻāpana liʻiliʻi loa ma mua o ka nalu o ke kukui ponoʻī. Ua kapa ʻia ka hopena ma hope o Baron John William Strutt, i ʻike nui ʻia ʻo Lord Rayleigh, he kanaka loea ʻepekema Pelekane nāna i wehewehe mua i ka hanana i ka hopena o ke kenekulia 19.
I ka hoʻopuehu ʻana o Rayleigh, ua like ka ikaika o ke kukui i hoʻopuehu ʻia me ka mana ʻehā o ka nalu o ke kukui. ʻO ke ʻano kēia, ua hoʻopuehu ʻia ke kukui me nā nalu pōkole (e like me ka uliuli a me ka poni) ma mua o ke kukui me nā nalu lōʻihi (e like me ka ʻulaʻula a me ka ʻalani).
ʻOiai ua hoʻopuehu ʻia ke kukui poni ma mua o ke kukui polū, ʻoi aku ka maʻalahi o ka maka kanaka i ke kukui polū a me ka ʻōmaʻomaʻo. ʻO ia ke kumu, ʻoiai he nui aku ka mālamalama poni i hoʻopuehu ʻia ma ka lewa, ua ʻike ʻia ka lani he uliuli iā mākou.
Ka Lewa o ka Honua
Ua haku ʻia ka lewa o ka Honua me nā kinoea like ʻole, me ka naikokene (ma kahi o 78%) a me ka oxygen (ma kahi o 21%). Loaʻa pū kekahi iā ia ka argon, ke kalapona ʻokikene, ka neon, a me kekahi mau kinoea ʻē aʻe i nā nui liʻiliʻi. He kuleana ko kēia mau ʻāpana i ka hoʻopuehu ʻana i ka mālamalama.
Ke komo ka lā i ka lewa, ua hoʻopuehu ʻia kona mau nalu pōkole i nā ʻaoʻao a pau e nā molekala kinoea. ʻOi aku ka maikaʻi o ka hoʻopuehu ʻana o ka mālamalama polū, me kona nalu pōkole, ma mua o ka mālamalama ʻulaʻula, me kona nalu lōʻihi. No laila, ke nānā aku kākou i ka lewa, ʻike kākou i ka lewa i hoʻopuehu ʻia me ka mālamalama polū mai nā ʻaoʻao a pau.
Eia nō naʻe, i ka wā e kau ai ka lā ma ka ʻaoʻao o ka lewa, e like me ka puka ʻana o ka lā a i ʻole ka napoʻo ʻana o ka lā, pono kona mālamalama e hele ma waena o kahi papa mānoanoa o ka lewa. Hoʻopuehu mua ʻia ka mālamalama polū i nā ʻaoʻao a pau a ʻaʻole hiki i ko kākou mau maka. I ka ʻaoʻao ʻē aʻe, ʻaʻole i hoʻopuehu nui ʻia ka mālamalama me nā nalu lōʻihi, e like me ka ʻulaʻula a me ka ʻalani, e like me ka mālamalama polū a hiki i ko kākou mau maka, no laila ʻike mākou i ka lā ma ke ʻano he ʻalani a ʻulaʻula paha.
Ka Haumia a me kona Hopena ma ke Kala o ka Lani
Ma waho aʻe o nā ʻāpana kinoea kūlohelohe i ka lewa, hiki i nā ʻano haumia like ʻole ke hoʻopilikia i ke kala o ka lani. Hiki i nā mea haumia e like me ka uahi, ka lepo, a me nā ʻāpana aerosol ke hana i ka Mie scattering, kahi ʻokoʻa mai ka Rayleigh scattering no ka mea pili ia i nā ʻāpana e like ka nui me ka nalu o ke kukui i hoʻopuehu ʻia.
ʻAʻole hilinaʻi nui ka mie scattering i ka nalu, no laila ua hoʻopuehu like ʻia nā kala āpau. Hiki i kēia ke hoʻolilo i ka lani i keʻokeʻo a hina paha. I nā kūlanakauhale me nā pae kiʻekiʻe o ka haumia o ka ea, ʻike pinepine mākou i nā lani e ʻoi aku ka palalulu a emi ka uliuli ma mua o nā wahi kuaʻāina maʻemaʻe.
Eia kekahi, hiki i ka haumia o ka ea ke hana i nā hanana ʻē aʻe e like me ka ua waikawa a me ka smog photochemical, ka mea e hoʻopilikia ʻole ai i ke kala o ka lani akā i ka maikaʻi o ka ea a me ke olakino kanaka.
Nā Hoʻololi Kau a me ka Wahi ʻĀina
Hoʻopilikia pū nā loli kau i ke kala o ka lani. I ke kauwela, ʻoi aku ka maʻemaʻe a me ka maloʻo o ka ea, e ʻoi aku ka maikaʻi o ka hoʻopuehu ʻana o Rayleigh a ʻoi aku ka uliuli o ka lani. I kēia manawa, i nā kau ua a i ʻole ka hoʻoilo, ʻo ke kiʻekiʻe o ka makū a me nā ao e uhi pinepine i ka lani, e ʻike ʻia ai he ʻano palalulu a hina paha.
Hoʻopilikia pū ke kūlana honua i ke kala o ka lewa. Ma nā ʻāpana polar, ʻo nā makani ikaika a me ka ea maʻemaʻe e hoʻolilo pinepine i nā lani polar i polū a moakaka. I ka ʻaoʻao ʻē aʻe, ma nā wahi kokoke i ka equator, ʻike ʻia paha ka lewa i keʻokeʻo a hina paha ma muli o ke kiʻekiʻe o ka makū a me ke ao pinepine.
Ka hopena
ʻIke ʻia ka lani a mākou e ʻike nei i kēlā me kēia lā he uliuli ma muli o ka hoʻopuehu ʻana o Rayleigh, kahi hanana kino kahi i hoʻopuehu ikaika ʻia ai ka mālamalama me nā nalu pōkole, e like me ka uliuli, e nā ʻāpana liʻiliʻi i ka lewa. ʻOi aku ka maʻalahi o ko mākou mau maka i ka mālamalama uliuli ma mua o ka mālamalama poni, no laila ʻike ʻia ka lani he uliuli ʻoiai ua hoʻopuehu nui ʻia ka mālamalama poni.
Eia kekahi, ʻo nā kumu like ʻole e like me ka haumia o ka ea, nā kau, a me ka wahi honua he kuleana ko lākou i ka hoʻoholo ʻana i ke kala o ka lani. Ma ka hoʻomaopopo ʻana i kēia mau hanana, hiki iā kākou ke mahalo maikaʻi i ka nani o ke kūlohelohe me he mea lā maʻalahi akā paʻakikī loa.
No laila, ke nānā aku ʻoe i ka lani polū i kahi lā mālamalama, e hoʻomanaʻo he ʻepekema hoihoi ma hope o kēlā nani i ʻike ʻia. Ua piha ke ao holoʻokoʻa i nā mea pohihihi, a ʻo ka lani polū kekahi o nā hanana he nui e kali ana e aʻo ʻia a hoʻomaopopo ʻia.
