New paper provides review of stress on ocean observing system
The COVID-19 pandemic killed millions of people and sickened hundreds of millions more. Since it was declared a pandemic on March 11, 2020, COVID-19 has had global public health and economic impacts that will take years to fully understand.
The pandemic occurred as the world is suffering increasing impacts of climate change. People need information to help them understand climate and make decisions on how to manage climate-related risks and opportunities. Individual measurements of meteorological, sea surface and subsurface variables directly improve the understanding of the Earth System, weather forecasting, and climate projections.
Like so many fields, the ocean observing community has been impacted by the pandemic. During the peak of the pandemic, some valuable oceanographic and marine meteorological data was not collected. What does that mean for the ability to provide scientific data and information about climate science, adaptation, and mitigation? A new paper explores those questions.
Ocean Observing System Under Stress
The paper appears in the Bulletin of American Meteorological Society (BAMS) and explores the effects of the COVID-19 pandemic on the executed Global Ocean Observing System’s (GOOS) in situ (in the original place) ocean observing. The GOOS is a system of complementary observing networks coordinated through the Observation Coordination Group of the Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational, Scientific and Cultural Organization (UNESCO), with monitoring support from joint World Meteorological Organization (WMO) - IOC in situ Ocean Observations Programmes Support (OceanOPS) center. The GOOS network of ships, buoys, and autonomous systems provides in situ ocean observations to create global time series of mean sea surface temperature, ocean-surface-to-ocean-depth ocean heat content, among many others. The paper focuses on the executed GCOOS (eGCOOS), which is the network’s focus on the short and long-term monitoring of essential climate variables (ECVs) used to monitor the environmental conditions immediately above the surface of the ocean, at the surface of the ocean, and throughout the water column down to the ocean/bottom interface.
Maintaining a global ocean observing system is challenging in normal times, and the pandemic put new strain on the system.
Short Term vs Long Term Observations
NCEI is an aggregation point for the ocean observing system. The data are used at NCEI and elsewhere for disseminating ocean climate monitoring information. A measure of the health of the system is the percent coverage as shown by the coverage statistics for NCEI Optimally Interpolated Sea surface temperature (OISST) and NCEI ocean heat content time series.
The paper provides a survey of the contributing components of the observing system which illustrates the impacts of the pandemic from January 2020 through December 2021. By evaluating each of the component systems—ships and independent platforms—the authors show that, while the pandemic had limited impact on short term observations, it caused more critical loss to longer-term (years to decades) observations. Historically, ship-based observations have formed the backbone of the GOOS. The cancellation of research cruises during the height of the pandemic led to the loss of over 3,000 discrete samples in the Eastern South Atlantic alone.
“The short-term geographic coverage capabilities were maintained mainly due to autonomous instrumentation such as those from the Argo ocean observing program and the Global Drifting Buoy Program which continued monitoring through the pandemic at the same level as before,” said Tim Boyer, lead author and Chief of NCEI’s Subsurface Oceanography Section. “They were able to monitor through the pandemic at the same level, but the floats and buoys were not able to be replenished at the same rate. Holes are now being seen in the system, especially in the Indian Ocean.”
Effects of Data Loss
The paper documents data loss at specific locations and in specific regions which resulted in the interruption of high-quality time series and geographic coverage. Near-real-time observations, such as sea surface temperature, subsurface temperature, and salinity are essential inputs for ocean and atmosphere data assimilation; their loss has direct consequences including an impact on the regional accuracy of weather and climate forecasts. The loss of the longer-term observations greatly impairs the monitoring of such crucial variables as ocean heat content, ocean carbon, and dissolved oxygen. Sustained time series are critical for the understanding of the ocean’s role in the Earth’s climate system.