Complex Greenhouse Gas dynamics in the Central Himalayas

Why in News?

Recently, scientists revealed the data on Greenhouse Gas (GHG) emissions around the Himalayan region.

• Data gathered by - Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous research institute under the Department of Science & Technology (DST).
• Data collection site - High-altitude research site in Nainital for over 5 years.
• Key findings - Greenhouse gas concentrations in the Central Himalayas are generally higher than those at other remote background sites.
• However, these levels remain lower than those typically found in urban and semi-urban settings.
• Contributing Factors - Natural processes and human activities together shape greenhouse gases.
• Key Green-house gases - Carbon dioxide (CO₂) and methane (CH₄), and carbon monoxide (CO) in the Central Himalayan region.
• Daily Variations - Carbon dioxide reaches its lowest levels during daylight hours due to active photosynthesis.
• Methane and carbon monoxide tend to peak during the day as mountain winds transport pollutants upward from lower elevations.
• Seasonal Variations - Carbon dioxide concentrations rise in spring, coinciding with increased biomass burning and limited vegetation cover.
• Methane levels are highest in autumn, likely linked to agricultural activities such as rice cultivation.
• Carbon monoxide peaks in late spring, suggesting a strong influence from regional pollution transport during this period.
• Long-term trends – The trends point to a steady rise in both carbon dioxide (2.66 ppm per year) and methane (9.53 ppb per year).
• These trends are even higher than those at Mauna Loa (a background site), underscoring the growing impact of anthropogenic emissions in the region.
• In contrast, carbon monoxide shows a gradual decline (3.15 ppb per year), possibly reflecting improvements in combustion efficiency or changes in regional emission sources.
• Significance - These comprehensive, high-resolution observations provide an essential baseline for validating satellite data, refining emissions inventories and improving atmospheric models.
• To disentangle the effects of biospheric uptake, regional emissions, and complex meteorological patterns that shape the region’s air quality and climate.

Reference

PIB| Complex Greenhouse Gas dynamics in the Central Himalayas