ParyavaranPushan · Class 9-10
Kaala dhuaan, safed barf: glacier jaldi kyun pighalte hain
Door kisi bhatte ya diesel truck ka dhuaan Himalaya ki barf ko kaise nuksaan pahuncha sakta hai?
Socho pehle… phir dekho jawab
Dhuein mein black carbon (kaalikh) hoti hai. Yeh hawa ke saath door tak jaati hai aur barf par jam jaati hai. Kaali satah zyada dhoop sokhti hai — barf garam hokar jaldi pighalti hai.
Garmi mein safed kapde kyun pehente hain? Kyunki safed rang zyada roshni reflect karta hai, kaala zyada absorb. Taaza barf dhoop ka bahut bada hissa waapas bhej deti hai — isse albedo (chamak ya reflect karne ki kshamta) kehte hain.
Jab kaalikh barf par baithti hai, albedo ghat jaata hai. Barf ab dhoop ko heat mein badalne lagti hai aur jaldi pighalti hai. Pighalne se neeche ki gehri, kam chamkili satah dikhti hai, jo aur zyada garmi sokhti hai. Yeh ek feedback loop hai — ek badlaav doosre ko aur tez karta hai.
Himalaya ke glacier Ganga, Brahmaputra aur Indus jaisi nadiyon ko paani dete hain. Isliye bhatta, lakdi ya khet jalana aur purane diesel engine sirf shehar ki hawa ka mudda nahin — pahad ki barf aur neeche ke kheton ka bhi mudda hai. Saaf eendhan aur behtar bhatta technology isi chain ko todti hai.
Ghar pe try karo
Do plate par ek jaisa ice cube rakho. Ek cube par chutki bhar raakh ya pisa koyla chhidak do. Dono ko dhoop mein rakho aur har 5 minute dekho — kaunsa pehle pighla?
Wow!
Kuch hazaar kilometre door ka dhuaan bhi ek glacier ka 'rang' badal kar usse jaldi pighla sakta hai.
3 sawaal
- Albedo ka matlab kya hai?
Jawab dekho
Satah kitni roshni reflect karti hai. Albedo reflectivity hai — safed barf ka albedo zyada, kaali satah ka kam.
- Barf par black carbon jamne se kya hota hai?
Jawab dekho
Barf zyada dhoop sokh kar jaldi pighalti hai. Kaali satah zyada roshni absorb karti hai, heat badhti hai, pighalna tez hota hai.
- Pighalne se neeche ki kam chamkili satah khulna aur aur zyada garam hona — isse kya kehte hain?
Jawab dekho
Feedback loop. Ek badlaav khud ko aur tez kare, use positive feedback loop kehte hain.
NCERT se jodo: NCERT Class 10 Science — hamara environment; Class 9 Geography — climate aur drainage (Himalayan nadiyan)