Date: 7th October 2025, Tuesday (11:00am – 12:00pm)
Presenter: Kashyapa Athreyas (CCRS)
Topic: Satellites, earth observation and weather

Abstract:
Weather affects all being on earth in their daily life. We try to predict weather to safeguard our life, interests and activities. We need to observe in order to gather enough information based on which, we predict the weather. In the recent decades, the importance of global coupling in the atmosphere is recognised not only internally, but also with ocean, surface and solar events. Satellites provide a good platform to observe global events on a regular basis. In this talk, I will go though the basics of earth observation from satellites, few of the instruments relevant to weather research that I have worked with. Thereafter, I will discuss some of the atmospheric studies I have been involved in such as, 1) inter-hemispheric coupling during the sudden stratospheric warming events, 2) gravity waves characterisation generated from thunderstorms in SEA region, and 3) estimation of latent heat of thunderstorms using satellite data.

Speaker Profile:
Kashyapa Athreyas is a Research Scientist at CCRS. He completed his Bachelor’s degree in Aerospace Engineering in 2011 at the University of Liverpool, UK, followed by a two-year joint European Master’s degree in Space Technology with a specialization in Systems and Control at Luleå University of Technology, Sweden, and Czech Technical University, Prague. He earned his PhD in 2018 from Nanyang Technological University (NTU), Singapore. Before joining CCRS in September 2025, he worked at NTU’s Satellite Research Centre, where he served as lead mission and systems engineer for four satellites, including two Earth observation missions, and contributed to several middle atmospheric coupling projects. His research interests include data assimilation, satellite remote sensing, atmospheric coupling, and machine learning–driven modelling.

Date: 14th October 2025, Tuesday (11:00am – 12:00pm)
Presenter: Trina Ng (CCRS)
Topic: What do we really know about sea-level rise in Singapore and Southeast Asia?

Abstract:
Global mean sea level (GMSL) has risen by over 20 cm since 1900, with the rate of rise accelerating in recent decades. While the contributions from thermal expansion and glacier melt are well understood, major uncertainties in the Antarctic ice sheet remain that drive the projected range of future GMSL widely. These gaps are critical for Southeast Asia, where dense population and economies are highly exposed. Singapore, in particular, has identified sea-level riser as an existential threat. In this talk, I will present local and regional projections of relative sea-level (RSL) rise for Singapore and Southeast Asia, highlighting both confident components of RSL rise and major gaps in our knowledge. The roles of regional ocean dynamics, ice sheet processes and vertical land motion in shaping future sea level in this region will be examined.

Speaker Profile:
Ms Trina Ng is a Research Scientist in the Department of Climate Research at Centre for Climate Research Singapore. She has a Masters of Science in Geophysics from Imperial College London, and has recently submitted her PhD thesis at Nanyang Technological University and awaiting defense. Her research focuses on understanding the drivers of relative sea-level change in Singapore and Southeast Asia, with a particular emphasis on how ocal and regional processes influence future projections. At CCRS, she leads the development of national sea-level projections that are directly relevant to national adaptation strategies, bridging scientific research with policy applications.

Date: 21st October 2025, Tuesday (11:00am – 12:00pm)
Presenter: Emma Ramsay (NTU)
Topic: Cooling Singapore and beyond

Abstract:
Urban overheating is one of the most pressing challenges facing tropical cities, with significant implications for health, equity, ecosystems, and overall livability. The Cooling Singapore 2.0 project is an integrated, multi-disciplinary project untangling the complexities of heat risks in Singapore at the intersection of science and policy. This talk will share insights from the Cooling Singapore 2.0 project and explore how these findings can inform action beyond Singapore’s borders. Key themes include the use of accessible and low-cost technologies to understand heat risks at local scales; approaches for monitoring and evaluating adaptation strategies; the role of nature-based solutions in cooling and resilience; and the importance of community engagement and cross-sector collaboration.

Speaker Profile:
Dr Emma Ramsay is a Lee Kuan Yew Postdoctoral Fellow at Nanyang Technological University, Singapore. Her research focuses on urban heat stress and climate adaptation. Working closely with decision-makers and local communities, she leads several collaborative research projects which aim to enhance climate resilience in Southeast Asian cities. She is a Lead Author on the Intergovernmental Panel on Climate Change (IPCC) Special Report on Climate Change and Cities. Prior to joining NTU, Emma earned her PhD at Monash University, Australia where she investigated climate-health challenges in urban informal settlements.

Date: 28th October 2025, Tuesday (11:00am – 12:00pm)
Presenter: Linda Yanti Sulistiawati (NUS)
Topic: Introduction to Climate Change Law

Abstract:
From Kyoto to Paris, climate change law has been discussed and contested. The talk will give a general understanding of climate change law including its actors, organizations, and stakeholders. It will provide an introduction to climate change in international environmental law, introduction to stakeholders in climate change law, key cases in climate change, and an introduction to developments in international law.

Speaker Profile:
Linda is a Senior Research Fellow at APCEL and also an Associate Professor of Law in Universitas Gadjah Mada, Indonesia. She received her doctorate in 2013 (honorary mentioned) from University of Washington School of Law, supported by the Fulbright PhD Presidential Program. She focuses on international environmental law issues, such as climate change, REDD+, marine plastic pollution, land issues and customary (adat) issues. Linda was a member of the delegation leading Indonesia’s negotiations of the Paris Agreement on Climate Change. Linda is a lead author of the Intergovernmental Panel on Climate Change’s Sixth Assessment Report and the Special Report on Cities and Climate Change. At APCEL, Linda focuses on comparative climate change law and policy in ASEAN.

Date: 25th November 2025, Tuesday (11:00am – 12:00pm)
Presenter: Chih-Chi Hu (CCRS)
Topic: Non-Gaussian Observation Errors for Satellite Data Assimilation

Abstract:
The observation error determines how much weight is put on the observation and is a crucial element in DA. Although the distribution of the observation error is assumed to be Gaussian in most DA methods, the actual distribution of the observation error can sometimes be non-Gaussian, mainly due to the presence of the representation error. In this presentation, I will first discuss a method for estimating the full distribution of the observation error in a non-parametric way. This will be followed by the discussion of approaches to incorporating non-Gaussian observation errors into variational DA method. Finally, I will present an implementation of non-Gaussian errors for all-sky satellite radiance observations in a cycling-DA global forecasting experiment.

Speaker Profile:
Dr Chih-Chi Hu is Research Scientist at CCRS. Chih-Chi obtained his MSc in Atmospheric Sciences at the National Taiwan University in 2016 and his PhD from Colorado State University in 2023. Before joining CCRS, he was a postdoctoral research Associate at Princeton University and Geophysical Fluid Dynamics Laboratory (GFDL, NOAA). Chih-Chi’s research focuses on improving the data assimilation (DA) methods from both theoretical and practical perspectives for numerical weather prediction (NWP). In addition to DA and NWP, he is also interested in machine learning and tropical cyclone research.