India At The Frontiers Of Climate And Ocean Research: Indian Scientific Expeditions To The Southern Ocean (ISESO) – IMPRI Impact And Policy Research Institute

Policy Update
Chetan Gupta

The Southern Ocean is the broad ocean that encircles the Antarctic continent. It is the second-smallest of the five oceans, larger than the Arctic Ocean but smaller than the Pacific, Atlantic, and Indian Oceans. The Southern Ocean covers approximately 21.96 million square kilometers and is generally defined as lying south of 60°S latitude.

Figure 1:The Southern Ocean
(Source: National Geographic) 

The Southern Ocean is a source and sink for several intermediate and deep water masses of the world’s oceans. It plays a vital role in the global circulation of water. It is significant in regulating the Earth’s climate through its currents, seasonal sea ice, and the ability to absorb heat and carbon dioxide from the atmosphere. It influences weather patterns and regional climates as it contains Antarctic Circumpolar Currents (ACC), the largest ocean currents on Earth. The Southern Ocean is a vital area for scientific research to understand climate change, ocean processes, and the impact of human activities on the environment.

Background

The Southern Ocean plays a substantial role in regulating the global climate. It also affects the Indian Ocean’s climate, which directly impacts India’s weather patterns, sea levels, and marine ecosystems. India conducts expeditions to the Southern Ocean to study these effects, understand climate variability, and  collect data on ocean-ice-atmosphere interactions, among other things. This region is relatively underexplored in terms of the Indian sector of the Southern Ocean (ISSO).

Figure 2:ORV Sagar Nidhi during Indian Expedition to the Southern Ocean
(Source: NCPOR, MoES)

The first Indian Expedition to the Southern Ocean began in 2004 as a pilot expedition and has continued with regular missions. India has completed 11 Indian Expeditions to the Southern Ocean. Recently, India conducted its 12th Indian Scientific Expeditions to the Southern Ocean (ISESO) in February 2025. ISESO is coordinated by the National Centre for Polar and Ocean Research (NCPOR), which is under the Ministry of Earth Sciences (MoES).

Objectives

• The relationships between physical, chemical, and biological elements across the Antarctic Circumpolar Current (ACC) and their roles in carbon sequestration and biogeochemistry.
• Air-sea-ice interaction and role of aerosols over the Southern Ocean.
• Repercussion of heat and mass exchange between subtropical and polar regions;
• Reconstruction of the paleo-environmental conditions for selected time slices during the last glacial-interglacial cycles to provide perspectives on future climate change;
• Generate relevant/critical sea truth and atmospheric data to contribute to global climate data sets and formulate climate models to mitigate/regulate climate change.

Functioning and Performance

The Indian Southern Ocean Research Program was initiated in 2004 when the pilot expedition took place onboard via research vessel ORV Sagar Kanya. Twelve multidisciplinary and multi-institutional expeditions have been carried out within this program, involving various national institutions, International organisations and universities. During the investigations, most of the observations were carried out in the region between 40◦S and 69◦S and 40–80◦E. It addresses various key scientific components, including the given research areas:

Research Areas under ISESO

• Atmospheric Sciences
• Physical Oceanography
• Biogeochemistry
• Chemical Oceanography
• Microbial Oceanography
• Biological Oceanography
• Optical Oceanography
• Palaeoclimatology
• Marine Geology 

Indian Scientific Expeditions to the Southern Ocean (ISESO) comes under the National Centre for Polar and Ocean Research (NCPOR), which is operating under the Ministry of Earth Sciences (MoES), Government of India. Located in Goa, the NCPOR is responsible for the polar and ocean research programmes. India’s institutional structure for polar and ocean science has become a multi-tiered system with multiple actors:

• NCPOR is a national nodal agency that plans, coordinates, and executes all of the Southern Ocean research program’s facets.
• National institutions, International organisations and Universities provide expertise in research collaboration.
• MoES provides overall policy frameworks, budget approval, and diplomatic engagement.

As of 2025, India has conducted 12 Expeditions to the Southern Ocean. The Indian Scientific Expedition to the Southern Ocean (ISESO) 2025 began in Mauritius. The two-month-long expedition was carried out onboard the South African oceanographic research vessel SA Agulhas. Various research vessels were used for the scientific expeditions, including ORV Sagar Kanya in 2004, Akademik Boris Petrov in 2006 and 2009, ORV Sagar Nidhi in 2010, 2011, 2012, 2013, 2015 and SA Agulhas in 2017, 2018, 2020 and 2025.

Figure 3:The team of 12th Indian Scientific Expedition to the Southern Ocean (ISESO) and research vessel SA Agulhas, 2025
(Source: NCPOR, MoES)

Figure 4:Research vessels used for the Indian scientific expeditions to the Southern Ocean, (a) ORV Sagar Kanya  (b) Akademik Boris Petrov (c) ORV Sagar Nidhi (d) S. A. Agulhas
(Source: A. Narayana Pillai, NCPOR)

Table 1: Chronological List of 12 ISESO Expeditions (2004-2025)
(Source: NCPOR, MoE)

Impact

The studies conducted in these expeditions are of prime importance in understanding the role of the Southern Ocean on regional and global climatic variability and its implications for living resources, biogeochemical cycles, and sea-level rise. The expeditions help determine the future course of action as the Southern Ocean impacts the Indian monsoon and overall climate factors. The results obtained from these expeditions are quite encouraging as they provided sufficient baseline data and information on various physical, biological and biogeochemical processes responsible for modulating global warming and climate variability.

The key findings have revealed:

• The rapid decline in Antarctic sea ice, which was assessed along the  satellite data
• Mapping of ocean fronts, water masses and heat changes in the Southern Ocean
• Measured surface carbon dioxide and its relationship with nutrients as well as biological activity.
• The linkage between seawater pH and tiny marine organisms called planktic foraminifera.
• Studied the ecology and abundance of coccolithophores (microscopic algae)
• Underwater ridges affect ocean conditions, and how iron and nitrogen influence biological productivity
• Plankton ecology, chlorophyll patterns and suspended particles have consolidated the understanding of the Southern Ocean’s role in carbon cycling and marine food webs.

Figure 5:Cruise tracks and multidisciplinary station locations for various Indian scientific expeditions to the Southern Ocean from 2010 to 2018
(Source: A. Narayana Pillai, NCPOR)

Emerging Issues

1. Rapid Decline of Antarctic Sea Ice: Reduction in the record of sea ice has increased unpredictability for sampling and safety.
2. Intensified Climate Change Impact: Southern Ocean’s changing dynamics threaten global climate stability. It influences ocean currents, atmospheric systems and Indian monsoon patterns.
3. Logistical and Operational Difficulties: Extreme weather, remote locations, and limited periods for safe operation create challenges for mission logistics and crew safety. Other challenges are the high cost of operations, advanced infrastructure, and specialised personnel for multidisciplinary research.
4. Understudied Ecosystem: There is a need for more comprehensive and long-term observations of ecosystem dynamics as areas of the Indian sector of the Southern Ocean (ISSO) are underexplored.
5. Geopolitical Competition and Compliance: The rising international competition for polar research access has resulted in the importance of compliance with global treaties (Antarctic Treaty System, etc.) and environmental protocols. It also increased participation in global scientific networks for data sharing.

Way Forward

The scientific and technological advancements in the twenty-first century are pushing new research frontiers. The geopolitical rivalries are compelling major countries to explore polar and ocean regions. The significant impact of climate change worldwide has also created multidimensional challenges. The strategic way forward is essential to ensure the sustainability and success of Indian Scientific Expeditions to the Southern Ocean (ISESO). The expeditions have made crucial progress, but the information gathered from these expeditions is insufficient to establish the Southern Ocean’s influence on the global climate. The long-term multidisciplinary monitoring and satellite-based technologies have become crucial. They prioritise studying critical changes in ocean circulation, biogeochemical cycles and ecosystems.

Moreover, high-quality data collection and open sharing (even collaboration) with international partners will improve climate models and forecasting of the Indian monsoon and agricultural impacts. There is a need to strengthen technological capabilities (like the use of ice-class research vessels and in-situ instruments) for navigation and sampling in extreme conditions. With the growing demand for polar research, we must enhance specialised scientific and technical human resources. It is of utmost importance to engage in global collaborations and adhere to international treaties to expand India’s scientific footprint. Most importantly, scientific outcomes should be integrated into national climate and environmental policies to enable the best possible decision-making, enhancing climate resilience.

References

1. Ministry of Earth Sciences. Official Website. https://www.moes.gov.in/
   
2. National Centre for Polar and Ocean Research. Southern Ocean. https://ncpor.res.in/pages/display/270-southern-ocean
   
3. Press Information Bureau. (2022, March 24). PACER Initiative. https://www.pib.gov.in/PressReleasePage.aspx?PRID=1809081

4. The Print. (2020, January 11). Indian research team sets sail to Antarctic Ocean to study climate change. https://theprint.in/science/indian-research-team-sets-sail-to-antarctic-ocean-to-study-climate-change/347169/

5. The Hindu. (2025, February 12). Three city students leave for Southern Ocean expedition. https://www.thehindu.com/news/national/kerala/three-city-students-leave-for-southern-ocean-expedition/article69208024.ece

6. The Indian Express. (2020, January 6). Pune scientist leads 34-member research team to Southern Ocean. https://indianexpress.com/article/cities/pune/pune-scientist-leads-34-member-research-team-to-southern-ocean-6201523/

7. Pillai, A. N., Ravichandran, M., & Jena, B. (2020, August). Indian scientific expeditions to the Southern Ocean: Comprehensive surveys to understand atmospheric, physical, and biogeochemical processes. Deep Sea Research Part II: Topical Studies in Oceanography, Volume 178, 104860. ScienceDirect. https://www.sciencedirect.com/science/article/abs/pii/S0967064520301065

8. Ghosh, S. (2025, July 4). India’s Antarctic quest makes valuable contributions to global research. Nature. https://www.nature.com/articles/d44151-025-00120-3

9. Scientific Committee on Antarctic Research. The Southern Ocean: A Global Ocean. United Nations Framework Convention on Climate Change. https://unfccc.int/sites/default/files/resource/4.9SCAR_Southern_Ocean_0.pdf

10. The Indian Express. (2020, February 15). Explained: Why this study by Indian scientists in Antarctic matters. https://indianexpress.com/article/explained/indian-scientists-antarctic-trip-climate-monsoon-6268763/

11. Ministry of Earth Sciences. Polar Science and Cryosphere (PACER) Scheme. https://moes.gov.in/schemes/polar-science-cryosphere?language_content_entity=en
    

About the contributor: Chetan Gupta is a Research Intern at Impact and Policy Research Institute (IMPRI). He is currently pursuing his Master’s degree in International Relations from South Asian University (established by SAARC nations), Delhi.

Acknowledgement: The author sincerely thanks Ms. Aasthaba Jadeja and the IMPRI team for their valuable support.

Disclaimer: All views expressed in the article belong solely to the author and not necessarily to the organisation.

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