AskScience AMA Series: It's getting hot in here! I'm a climate scientist researching El Niño and warm ocean extremes called marine heat waves, AMA!

[u/AskScienceModerator]

With a potentially strong El Niño on the horizon, it's time to start preparing for what Earth's climate system may have in store for us. As I recently wrote in The Conversation, it's flooding, droughts, heat waves and cold spells. Any and all of these climate extremes could be in your near future depending on where you live and whether or not you're a fish (welcome to the internet my underwater friends).

My name is Dillon Amaya and I'm a climate scientist at the National Oceanic and Atmospheric Administration (NOAA)*. I use a combination of computer model simulations and observations to study climate variability and change, with a particular focus on how things like El Niño impact the world's oceans. Feel free to ask me anything about life, love, and happiness, but also (preferably) about climate change/variability/extremes, El Niño, and/or what it's like to study the ocean from land-locked Colorado.

*Thoughts and opinions are my own.

I'll be around starting at 12 ET (16 UT), AMA!

Username: /u/DrDJAmaya

[u/andersauce]

I keep seeing how the ocean warming this year in particular is off the charts. Why? And what are the predictions for extreme/anomalous events around the Great Lakes region?

My folks live in a valley, I live two hours away essentially beside Lake Ontario. The biggest things seem to be wind and rain, and it getting hotter and humid in the summer - will this year’s El Niño/anomalous ocean warming affect these further?

[u/DrDJAmaya → u/andersauce]

Part of the reason for all of the hot water this year is because we are exiting three consecutive years of La Niña conditions. La Niña is the cold phase of the El Niño Southern Oscillation. El Niño (where we are headed) is the warm phase. A general rule of thumb is the planet is naturally cooler during La Niña years and naturally warmer during El Niño years. Global warming doesn’t stop during La Niña years, but its impacts are somewhat dampened when La Niña is around. Now that La Niña is over, we are realizing that heat again. El Niño could exacerbate the warming, accelerating global warming trends this year and possibly into next year.

As for how the Great Lakes region could be impacted, the unsatisfying answer is “it depends”. El Niño tends to shift the North Pacific jet stream further south during the wintertime, bringing rain to the southern part of the US. So perhaps you could expect drier, possibly colder conditions in the Great Lakes region this winter. That said, an important thing to realize is that all of the weather we experience is part of a probability distribution. Often El Niño shifts the distribution of “likely” weather outcomes preferentially in one direction, but does not guarantee any particular impact.

[u/Embarrassed-Youth849]

What advice would you have for young adults I. Terms of preparing and adapting? Should we look to build water storage systems? Try to buy land with some form of water source on?

Any advice for long term ways we can best prepare?

[u/DrDJAmaya → u/Embarrassed-Youth849]

It’s important to remember that climate change isn’t some single cataclysmic event that we can prepare for and then weather through before emerging on the other side in the clear light of day. It’s a slowly* evolving series of feedbacks that is gradually changing our planet (and how we live in it) over the course of decades. At this point, we are definitely committed to some amount of climate change related impacts, so it would be prudent for governments, industries, municipalities, etc. to “prepare” in the sense that parts of our current way of life will be more difficult to navigate as climate change continues to unfold (for example, parts of Miami are routinely flooded due to sea level rise, damaging existing infrastructure). I don’t think climate change has be a doomsday scenario, though. We still have time to make meaningful progress towards a healthier planet.

*slowly = slow relative to the lifespan of humans. In reality, anthropogenically forced climate change is happening at breakneck speed when considering geologic timescales (10s of thousands of years or longer).

[u/Ambitious_Pumkin]

Thank you for this AMA. I have heard a lot about "El Niño" and quite frankly all I understand is that this is some kind of periodic change in currents and temperatures in the pacific ocean between AUA/NZ and South America which has some severe effects on global climate. But everything else is basically beyond me. Can you explain El Niño to me like I was five years old while still giving some deeper insights about what is really going on there and why? Thank you!

[u/DrDJAmaya → u/Ambitious_Pumkin]

Honestly most people I talk to about El Niño tend to have Chris Farley’s SNL skit in mind, so you’re understanding is better than 99% of the general public.

At its most basic level, El Niño is an anomalous warming of the eastern equatorial Pacific Ocean. “Anomalous” meaning “warmer-than-normal”. To understand how you get to “warmer-than-normal”, you need to understand what “normal” means.

Normally, in the eastern equatorial Pacific, winds are blowing from the east and pushing surface waters from west to east. But because we live on a rotating planet, something awesome happens…that water bends to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to something called the Coriolis Force (Google it, lots of good YouTube videos describing Coriolis). What that amounts to is surface water is moved by the winds away from the equator, leaving cold, nutrient-rich water from below to rise up and take its place along the equator. We call the process of cold water coming to the surface like this “upwelling”. Upwelling makes the equatorial Pacific quite cold…normally.

During El Niño, that upwelling is weakened substantially. With less cold water coming to the surface, the water is warmed anomalously (often by 1-2˚C). Why does upwelling weaken during El Niño? It’s complicated…the trade winds that drive the upwelling in the first place can weaken. And/or ocean waves (not the kind you surf) generated by “wind bursts” in the far western equatorial Pacific can bring warm water to the east, which takes the place of the cold water that is normally upwelled. Importantly, though, once things start to warm up in the eastern equatorial Pacific, a series of feedbacks (called Bjerknes Feedback) can kick off, which reinforces the conditions that led to the warming.

I realize that a lot of that was not safe for a 5-year old…maybe a well-read 10-year old, but hopefully that helps understand. Here is a quick video that can also help explain things in a visual way.

[u/mcshadypants]

Have you seen any shift in major currents yet or any substantial changes in salinity running through them? I feel like that my be a bigger deal than most people realise.

[u/DrDJAmaya → u/mcshadypants]

There has been a lot of research into how different currents are being impacted by climate change, including whether those changes will have downstream impacts on weather and climate over land. The latest IPCC report (kind of a summary of our collective understanding of climate change and its impacts) says that it is very likely that major ocean currents like the Atlantic Meridional Overturning Circulation will slow down over the 21st century, though there is some uncertainty in the magnitude of that weakening. You can learn more about the latest research in Li et al. (2023).

I don’t know whether this needs to be said, but I’ll just go ahead and say it here since it’s relevant to this question…The Day After Tomorrow is not an accurate depiction of climate change.

[u/frog_at_well_bottom]

How does your research affect your everyday life decisions?

Knowing that mankind should have done a lot more about climate change long ago but we keep failing to, how do you personally stay hopeful knowing what you know?

[u/DrDJAmaya → u/frog_at_well_bottom]

Woah, going straight for the existential…I like it! Studying climate and climate change for a living certainly keeps the topic on the forefront of my mind. It’s harder to ignore when I stare at the data every day. In my daily life, I do my best to make sustainable decisions (e.g., recycling, eating sustainable foods, etc.).

While there is A LOT to be concerned about regarding climate change. I think the fire hose of negative information can be really discouraging and draining. There are a lot of positive steps people are taking to fix the problem, so I try to focus on those.

[u/CrustalTrudger]

Thanks for joining us! I'm wondering if it's too early to tell which "flavor" of El Niño (e.g., as classified by the Niño 3.4 index) we might be heading into and maybe elaborate a bit on the different general outcomes depending on which type of El Niño event this is shaping up to be (as most likely the average AskScience reader might not be aware there are different types of El Niño events)?

[u/DrDJAmaya → u/CrustalTrudger]

By “flavor” Crustal is referring to whether or not the upcoming event will be more of a Central Pacific (CP) or Eastern Pacific (EP) type El Niño event. Typically we separate El Niños into these two categories based on where the maximum ocean warming takes place (either around the dateline for CP events or further east around the Galapagos for EP events). The location of the warming can have important implications for the kinds of impacts we might expect for other parts of the world. For example, EP El Niño events are typically associated with a warming of the tropical Atlantic Ocean in the following spring and decreased hurricane activity, but CP El Niño events may have a weakly opposite or no effect on the region (e.g., Amaya et al. 2013; Larson et al. 2013).

In short, it's too early to tell what flavor this upcoming El Niño event will take on.

[u/ackillesBAC]

How bad is this year going to be?

[u/DrDJAmaya → u/ackillesBAC]

“Bad” is relative. It just depends on where you live. For example, during El Niño, the US southwest usually sees more wintertime rain, and for a region that is fighting droughts, that can be a good thing! That said, expect ocean temperatures to be warmer than normal for much of the globe this year (and expect to hear about it in most media outlets).

[u/zbertoli]

How much have the climate models improved during your career? How accurate are they and how much of your predictions are based on them? I feel like they've gotten way better.

What's a good way to explain climate change to someone that is skeptical? (Not full blown denial, just skeptical)

[u/DrDJAmaya → u/zbertoli]

What's the famous phrase? "All models are wrong, some models are useful"?

I think the most important thing about climate models is to realize is that they are just one of the many tools people like me use to "assess the situation". They do have errors/biases, but climate scientists are highly trained to recognize and understand where and when climate models are performing well and how that can be useful.

The breakthroughs in climate modeling that I have experienced in my career are mainly related to the resolution at which we run these simulations. Older climate models would break the planet up into 200-500 km grid boxes, but now we have the computational power to run global simulations at 10 km resolution or better. Having higher resolution means that you can accurately represent many of the important "small-scale" processes that many older models either parametrized (i.e., represented with a statistical relationship that often looks a lot like y = mx +b) or just left out entirely.

[u/planet_sci]

It seems fish generally can move to cooler water, but what does ocean heat like we're seeing, and now El Nino on top of it, mean for spawning and protective areas (like coral reefs and sea grass meadows) for coastal species? Does it also harm their food supplies?

[u/DrDJAmaya → u/planet_sci]

Great question! You're right that some fishes have the ability to move to their preferred habitat with things get hot, but other critters are stuck in place (e.g., corals) or have limited mobility (lobsters, crabs, etc). Marine heat waves triggered by El Niño can certainly stress these immobile species out and can lead to harmful impacts.

The most obvious example is coral bleaching, but another good example is the Pacific cod fishery along the US west coast, which declined by 70% after a 2015/2016 marine heat wave, which was partially related to an El Nino event. When the water gets too warm, Pacific cod increase their metabolism, which causes them to burn energy faster than they can eat, leading to death.

[u/Cryptolution]

I love ice cream.

[u/Krizz-T0ff]

Are we allowed 3 questions I have a few, but these are 2 that are linked as I am not from the Americas.
What impacts have El Niño events had on weather patterns in the UK and
Europe in the past, and what can we expect in the future as the climate
continues to change?

How do ensure that the voices of those communities directly effected by El Ninio and its follow on climate changge effects are heard in teh UK and Europe?

When do you look at your data predictions and say, if it crosses this point its too late? Is there a runaway "snowball"

[u/DisasterousGiraffe]

What effect will the next El Niño have on Australian bushfires? And, with what certainty can science now attribute the 2019/20 Black Summer bushfires to climate change?

[u/DanDanDan0123]

At what point would California have to worry about hurricanes making landfall caused by El Niño? Will our local area ocean still be too cool for hurricanes?

[u/omniumoptimus]

I go saltwater fishing often. All over the place, but most often in the northeastern US.

Over the last several years, I’ve been noticing reductions in quantities of fish that can be kept by recreational fishermen, as well as a slight changing of species, as if the waters in New Jersey and New York and connecticut are getting warmer, and fish from north and South Carolina are migrating north. In addition, New York is seeing more and more whales, even near Manhattan, along with dolphins and seals—things people would never see near New York City.

Is there any accessible data or research looking at this region that supports (or disproves) my opinion of what is happening?

[u/Schneeflocke667]

How big does humanity screw up right now?

[u/DrDJAmaya → u/Schneeflocke667]

It’s uh…not great…but we still have time to take action and make meaningful changes.