The vast array of ocean observations that underpin global climate and weather forecast models is being degraded by COVID-19, according to UNESCO's Intergovernmental Oceanographic Commission.

The computer models that produce weather and climate forecasts around the world rely on real-time observations taken by equipment on land, at sea and in the air. This global observation network, which is maintained by individual countries, research institutes and organisations, serves the global weather economy.

Over the past few months, there has been a decline in the availability and accuracy of some observations that feed into weather and climate models.

Back in early May, the World Meteorological Organisation reported that there had been a 75-80 percent reduction in meteorological observations from aircraft in response to COVID-19. This report also indicated that ground and ocean-based observations had been affected by the pandemic.

Now, new information from UNESCO reveals that there has been a 10 percent drop in data coming from the Argo network (an array of free-drifting floats that measure ocean temperature, salinity, currents and biological properties). While it's difficult to know how much of this decline in incoming ocean data has been caused by COVID, the virus is likely to have an ongoing impact.

"It is too early to tell to what extent this is due to COVID-19" says Mathieu Belbeoch, Argo Technical Coordinator at JCOMMOPS, "however the very low level of recent Argo float deployment compounds the situation, and this drop in data flow cannot be immediately remedied."

The ongoing challenges in maintaining ocean-based observations is two-fold. Governments and oceanographic institutes around the world have recalled many of their research vessels, limiting their ability to directly observe the ocean and to maintain automated observing equipment, like the Argo network. The other loss of data comes from the reduced non-scientific vessel traffic around the world. For example, the 'Ships of Opportunity Program' uses commercial and other non-scientific vessels to take ocean measurements. If these voyages stop, so do the observations.

While there are ongoing challenges to maintain effective weather and climate monitoring and ensure forecast accuracy around the world, the COVID-19 pandemic may offer an opportunity for a brighter future.

"Despite its significant impacts on the ocean observing system, the COVID-19 crisis can also be an opportunity for us to look at how to build greater resilience into our system," said Dr. Toste Tanhua, Co-chair of the Global Ocean Observing System.

"The impacts of COVID-19 have brought to light the inter-reliance of systems and some clear weak points that we can now work on to increase system efficiency and robustness." concludes Dr Tanhua.