Asutosh Acharya

National Center for Atmospheric Research · ACOM

Air pollution over the megacity New Delhi has gained significant attention in recent times. Local pollution, along with advection from upwind sources, long-range transport and festivities (e.g., Diwali) contributing large emissions from firecrackers, has led to high loading conditions over the city. In this study, we assess a particulate pollutant...

Black Carbon (BC) is an absorbing aerosol which has significant impact on the Earth - Atmosphere radiation balance and hence on climate. The variation of BC mass concentration and contribution of fossil fuel and biomass burning have been investigated over the Indian ocean sector of the Southern Ocean during austral summer. BC mass was in the range...

Pre-monsoon dust aerosols over Indian regions are closely linked to the monsoon dynamics and 11 Indian summer monsoon rainfall. Past observational studies have shown a decline in dust loading 12 over the Indian landmass potentially caused by changing rainfall patterns over the desert regions. 13 Such changes are expected to have far reaching impact...

This paper investigates the characteristics and impact of a major Saharan dust storm during June 14th -19th 2020 to atmospheric radiative and thermodynamics properties over the Atlantic Ocean. The event witnessed the highest ever aerosol optical depth (close to 2 during the peak of the storm) for June since 2002. The satellites and high-resolution...

Precipitation in the Arctic is expected to increase with implications to ecosystems and changes to atmospheric circulation. In the Arctic strong southerly wind, often known as atmospheric rivers, supply enormous moisture and heat into the Arctic and is expected to increase in future warming scenarios. The impact of these events on Arctic climate ch...

Hails observed at Ny Alesund, Svalbard in the Arctic during December–February 2018–19 is examined along with the atmospheric circulation patterns. When hail was noticed, surface warming and southwesterly—westerly winds were noticed. Atmospheric circulation pattern was characterised by high pressure anomaly over northwestern Europe. High clouds as w...

The high level of aerosol pollution in South Asia has a measurable impact on clouds, radiation, and precipitation. Here, exploring multiple observational data sets and simulations of the state-of-the-art ECHAM6-HAMMOZ chemistry-climate model, we report that the reduction in anthropogenic emissions during the COVID-19 lockdown period has enhanced pr...

The rapid evolution of science compels renewal of a knowledge-based policy, particularly in cold regions. In the Arctic and Himalayas, which have undergone a significant climate change, there is a disconnect between scientific knowledge and the practices of policy. The rising air temperatures, decreasing ice and snow, increasing precipitation and p...

The effect of atmospheric aerosols on Indian monsoon is one of the scientifically challenging and societally relevant research issues of the recent decades. Past studies have derived inferences mostly based on local emissions and their impacts thereupon. However, more recent studies have shown that the remote effects driven by aerosols elsewhere co...

The rapid evolution of science compels renewal of a knowledge-based policy, particularly in cold regions. In the Arctic and Himalayas, which have undergone a significant climate change, there is a disconnect between scientific knowledge and the practices of policy. The rising air temperatures, decreasing ice and snow, increasing precipitation and p...

Atmospheric concentrations of South Asian anthropogenic aerosols and their transport play a key role in the regional hydrological cycle. Here, we use the ECHAM6-HAMMOZ chemistry–climate model to show the structure and implications of the transport pathways of these aerosols during spring (March–May). Our simulations indicate that large amounts of a...

This paper investigates the characteristics and impact of a major Saharan dust storm during June 14th–19th 2020 on atmospheric radiative and thermodynamics properties over the Atlantic Ocean. The event witnessed the highest ever aerosol optical depth for June since 2002. The satellites and high-resolution model reanalysis products well captured the...

Hail observed at Ny Alesund, Svalbard in Arctic during December - February 2018-19 is examined along with the atmospheric circulation patterns. When hail was noticed, surface warming and southwesterly – westerly winds were noticed. Atmospheric circulation pattern was characterised by high pressure anomaly over northwestern Europe or in the North At...

Atmospheric concentrations of South Asian anthropogenic aerosols and their transport play a key role in the regional hydrological cycle. Here, we use the ECHAM6-HAMMOZ chemistry-climate model to show the structure and implications of the transport pathways of these aerosols during spring. Our simulations indicate that large amounts of anthropogenic...

The mechanisms behind Arctic warming and associated climate changes are difficult to discern. Also, the complex local processes and feedbacks like aerosol-cloud-climate interactions are yet to be quantified. Here, using the Community Earth System Model (CAM5) experiments, with emission enhancement of anthropogenic sulfate 1) five-fold globally, 2)...

Pre-monsoon dust aerosols over Indian regions are closely linked to the monsoon dynamics and Indian summer monsoon rainfall. Past observational studies have shown a decline in dust loading over the Indian landmass potentially caused by changing rainfall patterns over the desert regions. Such changes are expected to have a far-reaching impact on reg...

Clouds play a significant role in regulating the Arctic climate and water cycle due to their impacts on radiative balance through various complex feedback processes. However, there are still large discrepancies in satellite and numerical model-derived cloud datasets over the Arctic region due to a lack of observations. Here, we report observations...

In June, 2020 the Ministry of Earth Science published a detailed report named "Assessment of Climate Change over the Indian Region" on human induced climate change and its effect over India. The present work is collaboration between multidisciplinary people to summarize and translate the report in several Indian languages in order to disseminate th...