A global aerosol model based on the analysis of 30-year ground measurements from AERONET (AEROEX model): Implications for satellite-derived aerosol retrievals.

The AErosol RObotic NETwork (AERONET), established in 1993, now spreads across 900 global sites, has about three decades of ground-based aerosol measurements. An aerosol model characterizes the physical and optical properties of atmospheric particles used in satellite and ground-based retrievals and climate simulations. Earlier aerosol models, developed using limited data (∼10-12 years, ∼250 sites), could not capture recent environmental shifts and associated changes in aerosol emissions driven by industrialization, land use changes, intensified wildfires, and dust storms.

Rapid changes in warm and cold extremes in recent decades and their future projections for India.

Assessing changes in temperature extremes is essential for understanding the impacts of global warming on agriculture and public health in a populous and developing country like India. This study analyses trends in warm and cold extremes using surface observations (1980-2020) and Coupled Model Intercomparison Project Phase 6 (CMIP6) data. We find a significant increase in warm days (2-7 days/decade) and warm nights (2-8 days/decade) across India, particularly in the Northeast (NE), Northwest, and Peninsular (IP) regions during 1980-2020.

Surface ozone pollution-driven risks for the yield of major food crops under future climate change scenarios in India.

This study provides a comprehensive assessment of surface ozone (SurfO) evolution in India under the future shared socio-economic pathway scenarios (SSPs) of the Coupled Model Intercomparison Project phase-6 (CMIP6), and its implications for changes in relative yield loss (RYL) of wheat, rice and maize. Scenarios with insufficient efforts to reduce the emission of precursors (e.g.

Impact of the National Clean Air Programme (NCAP) on the particulate matter pollution and associated reduction in human mortalities in Indian cities.

The study of particulates in cities holds significant importance in the evaluation of atmospheric conditions, comprehension of health ramifications and provision of valuable insights for the development of efficient pollution abatement measures and policies. Governments worldwide are currently enacting rigorous regulations aimed at mitigating particulate matter (PM), as it seriously affects air quality, public health, ecosystem, and visibility over a region. In this context, the Indian government launched the National Clean Air Programme (NCAP) in 2019 to reduce the PM emissions to 20-30 % by 2024-25, as compared to that of 2017-18, by enforcing city-specific policies and mitigation strategies.

An in-depth analysis of the impact of environmental drivers on the variability of phytoplankton community in the Arabian Sea during 2010-2021.

This study examines the long-term changes in phytoplankton size classes (PSCs) in the Arabian Sea (AS) using the remote sensing reflectance () data collected over 12 years (2010-2021) from the Moderate Resolution Imaging Spectroradiometer (MODIS). The spectra were inverted to chlorophyll-a (Chl-a) concentrations using a non-linear optimisation method, which were then used to estimate the PSC using a region specific three-component model. The analysis is carried out for all four seasons, , winter (December-February), pre-monsoon (March-May), monsoon (June-September) and post-monsoon (October-November).

Warming-induced soil moisture stress threatens food security in India.

Soil moisture (SM) interconnects various components of the Earth system and drives the land-atmosphere feedbacks and food production. However, around 40% of global vegetated land experiences SM drying. India is one of the global hotspots of land-atmosphere interactions and an extensively agrarian economy, but underexplored in terms of SM dynamics and its ramifications on food security.

Global tropical and extra-tropical tropospheric ozone trends and radiative forcing deduced from satellite and ozonesonde measurements for the period 2005-2020.

Tropospheric ozone (TPO) is considered as a "near-term climate forcer", whose impact on climate depends on its radiative forcing (RF), which is a change in the Earth's energy flux. Here, we use the ground-based and satellite measurements during the period 2005-2020 to deduce the trends of TPO, which is significantly positive in the tropical and extra-tropical northern hemisphere (0.2-0.

Trends in atmospheric water vapour over the Thar Desert during Indian Summer Monsoon period of 2003-2020.

The Thar is the most densely populated desert in the world, which supports diverse ecosystems and human endeavours such as agriculture and socioeconomic activities. Water demand and supply in the Thar play an essential role in regulating the socioeconomic activities of the region. Inland water and precipitation aid the movement of water in the Thar Desert.

Increased global cropland greening as a response to the unusual reduction in atmospheric PM₂.₅ concentrations during the COVID-19 lockdown period.

The devastating effects of COVID-19 pandemic have widely affected human lives and economy across the globe. There were significant changes in the global environmental conditions in response to the lockdown (LD) restrictions made due to COVID-19. The direct impact of LD on environment is analysed widely across the latitudes, but its secondary effect remains largely unexplored.

Elucidating the changing particulate matter pollution and associated health effects in rural India during 2000-2019.

Atmospheric pollution is a serious problem in many countries, including India, and it is generally considered as an urban issue. To fill the knowledge gap about particulate pollution and its adverse health effects in rural India for well-informed region-specific policy interventions, we present new insights on the rural pollution of India in terms of PM. Here, we analyse PM pollution and its associated health burden in rural India using satellite and reanalyses data for the period 2000-2019.

Sources, variability, long-term trends, and radiative forcing of aerosols in the Arctic: implications for Arctic amplification.

Atmospheric pollution in the Arctic has been an important driver for the ongoing climate change there. Increase in the Arctic aerosols causes the phenomena of Arctic haze and Arctic amplification. Our analysis of aerosol optical depth (AOD), black carbon (BC), and dust using ground-based, satellite, and reanalysis data in the Arctic for the period 2003-2019 shows that the lowest amount of all these is found in Greenland and Central Arctic.

Observed evidence for the impact of coastal currents on the recurrent Noctiluca scintillans blooms in the northwest Indian Ocean coast.

Recently, South Eastern Arabian Sea (SEAS) experiences recurrent winter blooms of green Noctiluca scintillans with serious ecological consequences. Here, the analysis of green N. scintillans blooms in SEAS for the past three consecutive years (2018-2021) is presented.

Browning of vegetation in efficient carbon sink regions of India during the past two decades is driven by climate change and anthropogenic intrusions.

Accurate estimation of carbon cycle is a challenging task owing to the complexity and heterogeneity of ecosystems. Carbon Use Efficiency (CUE) is a metric to define the ability of vegetation to sequester carbon from the atmosphere. It is key to understand the carbon sink and source pathways of ecosystems.

Air quality trends in rural India: analysis of NO pollution using satellite measurements.

India is a country with more than 67% of its population (947 million) residing in rural areas and 33% in urban areas (472 million) as of 2020. Therefore, health of the people living in rural India is very important for its future development plans, economy and growth. Here, we analyse the rural air quality using satellite measurements of NO in India, as the sources of NO are well connected to the industrial and economic uplift of a nation.

The increasing atmospheric CO over India: Comparison to global trends.

Atmospheric CO is the key Greenhouse Gas in terms of its global warming potential and anthropogenic sources. Therefore, it is important to analyze the changes in the concentration of atmospheric CO to monitor regional and global climate change. Here, we use ground-based and satellite measurements for the 2002-2020 period to assess CO over India.

Improvements in SO pollution in India: role of technology and environmental regulations.

India relies heavily on coal-based thermal power plants to meet its energy demands. Sulphur dioxide (SO) emitted from these plants and industries is a major air pollutant. Analysis of spatial and temporal changes in SO using accurate and continuous observations is required to formulate mitigation strategies to curb the increasing air pollution in India.

The Increasing Surface Ozone and Tropospheric Ozone in Antarctica and Their Possible Drivers.

A comprehensive analysis of the temporal evolution of tropospheric ozone in Antarctica using more than 25 years of surface ozone and ozonesonde measurements reveals significant changes in tropospheric ozone there. It shows a positive trend in ozone at the surface and lower and mid-troposphere, but a negative trend in the upper troposphere. We also find significant links between different climate modes and tropospheric ozone in Antarctica and observe that changes in residual overturning circulation, the strength of the polar vortex, and stratosphere-troposphere exchange make noticeable variability in tropospheric ozone.

Anthropogenic forcing exacerbating the urban heat islands in India.

Urban heat island (UHI) phenomena is among the major consequences of the alteration of earth's surface due to human activities. The relatively warmer temperatures in urban areas compared to suburban areas (i.e.

The signs of Antarctic ozone hole recovery.

Absorption of solar radiation by stratospheric ozone affects atmospheric dynamics and chemistry, and sustains life on Earth by preventing harmful radiation from reaching the surface. Significant ozone losses due to increases in the abundances of ozone depleting substances (ODSs) were first observed in Antarctica in the 1980s. Losses deepened in following years but became nearly flat by around 2000, reflecting changes in global ODS emissions.