How La Niña and Climate Change May Be Enabling Our Current Parade of Atmospheric Rivers | The Canadian News

La Niña is playing a role in allowing our current parade of atmospheric rivers across the Pacific and there may also be a connection to climate change.

Faron Anslow, climate monitoring and analysis leader for the Pacific Climate Impacts Consortium, explains that “the general source of almost all atmospheric rivers here and around the world is the tropics.”

“The water evaporates from the warm ocean there and rises through thunderstorm activity and eventually the water vapor moves north and gets trapped in the storm tracks that then carry the water to BC.”

“With the next storm looming, it appears that this water came from near the Philippines and this has been a feature that has been with us for much of the year.

“For reasons that are still not entirely clear to us, water vapor has been creeping into storms repeatedly for months.”

Located off the coast of the Philippines, is an area of ​​the Pacific Ocean called Indo-Pacific temperate pool. One scientific paper He calls this region the “steam engine” of the world. “

Trend stories

• 

  Moderna CEO Says COVID-19 Vaccines May Be Less Effective Against Omicron Variant

• 

  Here’s why the WHO omitted 2 Greek letters to name the new ‘Omicron’ variant

“This is an area of ​​the planet with the warmest ocean temperatures anywhere, and because of that, it is able to withstand what we call really deep convection, where there are thunderstorms that go from the surface to the stratosphere. “Anslow said.

According to a peer-reviewed scientific article in Scientific advances, This warm Indo-Pacific pool has expanded and warmed in the last century due to climate change.

“Research shows that warmer ocean temperatures in that region are expanding. Basically, as all regions warm, the areas that are reaching this critical threshold for convection are increasingly expanding north and south, ”Anslow said.

“My hypothesis is that the expansion is making it a little easier for these storms to collect this moisture and bring it across the Pacific Ocean towards us.”

In addition, La Niña, which is currently occurring, is also enhancing the export of moisture from the Indo-Pacific Warm Pool.

“The La Niña pattern is for warmer than normal ocean temperatures in that warm area of ​​the pool,” Anslow said.

“So La Niña in this case is enhancing that warm pool effect and allowing all this moisture to be exported.”

It shows clearly in this upcoming atmospheric river.

“This current storm has a very clear wet trail running from British Columbia to quite close to the Philippines, so it goes across the Pacific Ocean, more than 10,000 km.”