Sachchida Nand Tripathi

The 2025 Alexander von Humboldt Medal is awarded to Sachchida Nand Tripathi for outstanding and societally relevant research in the field of atmospheric science, directly affecting populations in rural and urban developing areas in India.

Sachchida Nand Tripathi's career stands out for combining high-quality scientific research with practical solutions to environmental challenges, especially in developing rural and urban areas. He has numerous publications (many of which have been published in high impact journals), underscoring his significant international standing in atmospheric science. One of Tripathi's key achievements was leading a study that showed how aerosols can impact clouds during the Indian summer monsoon. This finding is crucial for understanding rainfall patterns and their influence on water resources and agriculture in the region. His research identified aerosols as the single most important component that determines Indian air quality, weather, global climate and public health. He has adapted an interdisciplinary approach has led to technological solutions and concrete policy guidelines for securing clean air in India.

Tripathi also led a project that focused on determining the impact of air pollution on the Taj Mahal, that involved an extremely novel measurement/modeling approach to show the specific sources of the particles responsible for discoloring of the Taj Mahal. This highly impactful work resulted in substantial media coverage of the problem, and policies were put in place in Agra to reduce key air pollution sources impacting the Taj Mahal.

Measuring pollution and understanding its source requires networks of inexpensive sensors. Sachchida Nand Tripathi deployed a network of these sensors, of his own design, at 1400 locations. He has developed innovative approaches to qualify the accuracy, affordability and feasibility of indigenously built sensor-based network technologies for nationwide urban air quality monitoring. This has enabled a paradigm shift by making it possible for the decision makers, climate researchers and environmental groups to access affordable and reliable air quality monitoring technologies over a wider and denser scale.

Sachchida Nand Tripathi's recent research has discovered the genesis of night-time air pollution. It provides mechanistic understanding of nanoparticles growth preceding severe haze pollution in Delhi, which is due to biomass burning emissions.

It is also important to point out that he is now working closely with policy makers who are implementing his approaches in governmental policy decisions. His work not only advanced our scientific knowledge, but has also made a real difference in improving people's lives in the face of environmental challenges. This will impact the livelihoods of millions of people currently living in poverty, in India.