2026 STAR Seminars

STAR Science Seminar Series

Title: Pelagic Sargassum in the Atlantic Ocean: what happened in the past 20 years?

Presenter(s): Chuanmin Hu, University of South Florida

Sponsor(s): NOAA Ocean Color Coordinating Group (NOCCG)

Remote Access: https://meet.google.com/hnd-zams-bgo

Seminar Contact(s): Cara.Wilson@NOAA.gov

Abstract: Pelagic Sargassum, one type of brown macroalgae or seaweed, has been known to be abundant in the Sargasso Sea since its first report in the 15^th century by Christopher Columbus. In 2011, however, large amounts of Sargassum started to appear in the Caribbean Sea, causing adverse impacts on the coastal environments and turning an otherwise critical open-ocean habitat into a coastal hazard. Since then, the research community has spent enormous effort in finding better ways to assess its spatial distributions and temporal changes as well as improved understandings of the reasons behind these changes. Here, using satellite observations and other data, we first review the remote sensing techniques used to map and quantify pelagic Sargassum, and then report a possible regime shift in Sargassum distributions in the Atlantic Ocean, characterized by the emergent Great Atlantic Sargassum Belt and dramatic decline in Sargassum abundance in the north Sargasso Sea. We also discuss the possible reasons behind such a regime shift and pathway forward in future Sargassum research.

Slides, Recordings, Other Materials: Slides can be found at this link about 24 hours after the live webinar: https://www.star.nesdis.noaa.gov/star/PastSeminars_NOCCG.php

STAR Science Seminar Series

Title: Advances in Radar Altimetry for Observing Sea State and Sea Level

Presenter(s): Christopher K. Buchhaupt (cbuchhau@umd.edu), CISESS/ESSIC/UMD

Sponsor(s): STAR Science Seminar Series

Seminar Contact(s): Deirdre.Byrne@noaa.gov

Remote Access:
Time zone: America/New_York
Google Meet joining info
Video call link: https://meet.google.com/uyt-xzpe-vhs
Or dial: (US) +1 402-545-0132 PIN: 663 176 768#
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Abstract: Since 2010, a new generation of space-based ocean observations has significantly improved the monitoring of the ocean surface, providing more detailed measurements of sea-state and sea level, and making it easier to capture changes in ocean conditions, particularly in coastal and high-energy regions. Those observations play an important role in weather and ocean forecasting, long-term assessments of ocean conditions, and studies of how waves and sea level influence coastal, reef, and offshore environments.

This presentation introduces new parameters related to wave motion enabled by recently developed algorithms. The new parameters are presented and discussed, together with their effects on estimates of sea level and wave height. Example cases include gridded sea level and sea-state results that illustrate how these products change when the new parameters are taken into account. The presentation will additionally provide a brief overview of ongoing efforts to extend these approaches to polar regions.
Co-authors: Alejandro Egido, ESTEC/ESA; Doug Vandemark, University of New Hampshire; Hui Feng, University of New Hampshire

Slides, Recordings Other Materials:
https://www.star.nesdis.noaa.gov/star/documents/seminardocs/2026/20260212_Buchhaupt.pdf

STAR Science Seminar Series

Title: Using Long-term Satellite Ocean Color Records for Detecting Persistent Oceanic Trends

Presenter(s): Myung-Sook Park, Korea Institute of Ocean Science & Technology (KIOST)

Sponsor(s): NOAA Ocean Color Coordinating Group (NOCCG)

Remote Access: https://meet.google.com/hnd-zams-bgo

Seminar Contact(s): Cara.Wilson@NOAA.gov

Abstract: Phytoplankton play a central role in marine biogeochemical processes and ocean ecosystems, and satellite ocean color observations provide a powerful means of monitoring their variability through changes in optical properties of seawater. However, interpreting long-term signals from ocean color data remains challenging due to the strong influence of natural variability and measurement uncertainties. In this seminar, we introduce an analysis framework that integrates long-term environmental records with multi-decadal satellite ocean color observations to better separate persistent signals from dominant modes of natural variability. By combining complementary datasets and applying signal-separation techniques, this approach enables a clearer examination of long-term changes in ocean optical properties without relying on short-term fluctuations.We discuss how variations in light absorption and scattering"linked to changes in phytoplankton and dissolved constituents"can be systematically examined using sustained satellite observations. Rather than focusing on specific regional outcomes, the emphasis of this seminar is on the methodological approach, data consistency, and the implications for long-term monitoring. This work highlights the importance of continuous, well-calibrated satellite ocean color records as an essential component of operational ocean monitoring systems and their applications to ecosystem and fisheries-relevant studies.

Slides, Recordings, Other Materials: Slides can be found at this link about 24 hours after the live webinar: https://www.star.nesdis.noaa.gov/star/PastSeminars_NOCCG.php