In 2022 Alaska experienced its 17th-warmest calendar year, while the rest saw their fifth-warmest year in recorded history. This is because the average global ocean temperature continues breaking records as it did last year.
Brian Brettschneider, National Weather Service climate researcher, is back in our Ask a Climatologist segment.
Brettschneider also said that although Alaska’s temperature didn’t break any records in 2022 it is important to remember that they are still much higher than they were previously. He says that we have been fortunate to have three La Nina years consecutively. However, that is likely to change.
Listen:
This transcript has been lightly edited to improve clarity.
Brian Brettschneider – Typically, in a La Nina season, our region is typically cooler than the global average. And so when we say, “Oh, you know, 17th doesn’t sound too bad, it’s not the apocalyptic terms that we often hear,” it is important to keep that regional-versus-global perspective in mind.
Casey Grove – Gotcha! You recently tweeted about this, and how even though it’s a La Nina-year, it can still be quite significantly warm. We should be on the lookout for El Ninos next year. What was that you meant? What could we possibly expect in the next El Nino?
Brian Brettschneider – Alaska has a pretty consistent record of having cooler La Ninas than the norm. However, as you mentioned, there is more variability so it’s possible to have warmer La Ninas than usual. About two-thirds are actually cooler than normal. El Ninos are, however, uniformly warm in Alaska. The question in El Nino years is whether we will be record warm, warm or really, really warm. These are just some of the possibilities that El Nino years offer. The Climate Prediction Center’s latest outlook shows that we are moving away from La Nina and into “ENSO (El Nino Southern Oscillation neutral”), with a tilt towards possible El Nino conditions in the fall. There is a lot of consensus on this, but it’s still a long way out. They are cautious with their language. However, there are signs that this could be the direction we are heading.
Casey Grove – That’s very interesting. That seems a faraway place. What indicators point to that?
Brian Brettschneider. So both dynamic and statistical models are looking at the development of the trade winds over the tropical Pacific. Some of the ocean current movement, subsurface ocean heat, all are trending in a way that would suggest that we are going to be leaving the La Nina situation. We could also flip the switch to an El Nino.
Casey Grove – I was glad that you mentioned the ocean temperatures because I wanted to discuss them. Another headline I saw recently was that we had broken the global record for the ocean temperature going up. In the context of all other indicators, what does this mean?
Brian Brettschneider – There is variability in the climate system from year to year. If you look at time series, it can look a bit jumpy. La Nina is a prime example. We’ve seen a few La Nina years consecutively. This generally impacts the top 100m of the ocean. There, wind patterns and upwellings of water along the coast of South America can cause cooling. That’s only the top layer. The ocean acts almost like a sponge to absorb atmospheric heat. When we look deeper, not just at the surface which is affected year-to-year by variability, we see that the top 2000 meters absorb a huge amount of heat from the atmosphere. This doesn’t change much from year to year. There is very little variability. It absorbs more heat, which is why it doesn’t change. It’s a steady, upward trend. 2022 broke the ocean heat content record that had been held since 2020. This record was set the previous year. This is a very linear trend. We expect that 2023 will break the previous record of just last year. The oceans also absorb 90% of the heat trapped in the atmosphere. This is the warmth that will last for many years to come.
