TORONTO – Could the height of waves in cold water have something to do with how ice forms in clouds? There may be a connection, according to new analysis of a research vessel’s voyage through the Chukchi Sea, which could help make climate models more accurate.
As global warming causes more sea ice to melt in the Arctic region, it allows stronger winds to whip up longer waves, sending sea spray higher into the air. New study, published last month Journal Geophysical Research Letters, looks at how particles from waves can fuel the growth of ice-forming clouds.
Cloud formation, and how it actually happens, is an important part of weather systems, and helps us understand how to track something called the surface heat budget: the associated body of water temperature with its How much heat is needed to increase from winter minimum to maximum summer. This surface heat budget then informs climate models that researchers use to track climate change.
“The insights gained from this study are very important if we are to accurately predict the effects of global warming on the Arctic,” it said in a press release.
This new study looks at data collected by a research vessel on an Arctic cruise in the Chukchi Sea north of the Bering Strait in November 2018. The ship was making meteorological observations and analyzing the different types of organic particles that sea spray throws into the air from the crest of the waves.
To take these measurements, the ship’s researchers launched particle sensors into the clouds using balloons. They also took measurements from different depths of the ocean to understand how the roughness of the ocean on any given day is related to the weather and ocean particles interacting with the clouds.
The particles they were most interested in are called ice-nucleating particles (INPs). These are particles that essentially act as “seeds” in the sky, fueling the growth of ice in clouds by freezing droplets.
During the voyage of the research vessel, there were various weather phases. During the first phase, the winds were strong, but the air temperature was also “reasonably high”. The air temperature has dropped over a period of three days. In later research, during a two-day period, wind speed peaked, but air temperature and water temperature varied – sometimes – by as much as 10 degrees.
“The sea surface temperature during this month was the record maximum, which promoted a delay in the progress of sea ice in the region,” the study said.
The study found that during these high-wave conditions, there were higher concentrations of INPs, “corresponding to a greater amount of ice crystals in the low-level clouds.” During these conditions, the concentration of INP increased by 10-fold compared to the earlier period.
When the researchers analyzed the aerosols themselves, they found “a high amount” of [organic carbon] is associated with a high content of sea salt” which suggests that sea spray is a major source of INP found in clouds.
The study noted that the Chukchi Sea is also a “marine biological hot spot”. It is relatively shallow and has well-mixed ocean layers, in which particles close to the bottom can be pulled to the surface under rough conditions.
The discovery brings researchers closer to understanding what drives ice-forming clouds, which are an important part of understanding Arctic weather, the release said.
“Ice clouds reflect much less shortwave solar radiation than water clouds, and thus cloud phase greatly affects the surface heat budget of the polar regions,” the release said. “They can also increase the amount of snowfall, which in turn positively affects sea ice formation.”
More studies are needed for a more in-depth look at how the cycle works, and how climate change interacts with it, but researchers say it brings us one step closer.
Jun Inoue with the National Institute of Polar Research said, “Understanding the relationship between cloud formation and the new ocean state resulting from recent Arctic sea-ice decline can provide efficient weather and sea-ice forecasts as well as future climate projections.” be important for.” in Japan, the release said.