Computer models show heat waves in north Pacific may be due to China reducing aerosols
Hailey Kempf
News Article: https://phys.org/news/2024-05-north-pacific-due-china-aerosols.html
Journal Article: https://www.pnas.org/doi/10.1073/pnas.2313797121
“Warm blob” events, or marine heatwaves, have occurred in the Northeast Pacific Ocean (NEP) since the early 2010’s. These events are characterized by unusually warm sea surface temperatures (Bond et al 2017). Warm blob events can cause fish die-offs and harmful algae blooms, which in turn can negatively affect marine ecosystems of the Pacific (Smale et al 2019, McCabe et al 2016). These events can also cause millions of dollars in agricultural loss, causing negative socioeconomic impacts (Smith et al 2021). Some previous studies have linked the cause of the warm blob events to the El Niño and Southern Oscillation (Baxter and Nigam 2015) and GHG emissions (Frölicher et al 2018), but because of the periodicity of El Niño and the ongoing warming due to GHGs, Wang et al. wanted to explore the hypothesis that a recent aerosol abatement in China could contribute to the warm blob event in the NEP.
Researchers at the Ocean University of China used models to investigate the possible connection between the abatement of aerosols in China and the recent NEP warm blob events (2014, 2015, and 2019). The resulting peer-reviewed journal article was taken up by Bob Yirka at Phys.org, an online news service that covers topics in all fields of science and technology.
The researchers at the Ocean University of China specifically used two phases of model simulations from the Coupled Model Inter-comparison Project (CMIP): CMIP5 and CMIP6. Both ensembles use the same 12 climate models to detect temperature anomalies. However, CMIP5 uses forces that simulate if East Asian aerosol emissions flattened in the 2000s, while CMIP6 simulates if East Asian aerosol emissions saw a steep decline in the 2000s. The authors then used statistical analyses to attribute warming to various sources. Using many modeling techniques, the authors were able to validate that the NEP warm blob event was not, in large part, a result of GHG emission-related warming or El Niño-related warming. They also ruled out atmospheric circulation, which was too variable to explain the warm blob events in the NEP.
Comparing data that excluded all internal warming signals, the authors found that CMIP6 was much better at predicting the NEP warm blob events than CMIP5, indicating that the cause of the warm blob events could be attributed to the decrease in aerosol emissions in East Asia in the 2000s. Additionally, it was found that aerosol reduction not only directly affects the radiative forcing of the NEP, but it induces an atmospheric circulation response that decreases winds over the NEP which contributes to its warming. Finally, the authors investigated the relative importance of the location of aerosol reduction and found that East Asia was the most prominent contributor to warm blob events, followed by South Asia and Europe.
Yirka does a great job of succinctly describing the article without getting too technical, which is especially impressive for a methods-heavy article such as the one by Wang et al. He provides lots of background information on why the warm blobs are relevant, describes the recent abatement of East Asian aerosol emissions, and how aerosol reduction in one area of the world can cause warming in another. He then goes on to describe the model method in simple terms: that the two model ensembles included “one where emissions from East Asia remained as they were over the past several decades and one where they dropped in the way they had in reality.” Finally, he explains not only the results of the study, but the mechanism behind how aerosol reduction in China could affect the NEP through atmospheric circulation changes. None of the really major points were omitted from the news article, yet the news article is only around 500 words and explained in terms most people would understand.
One minor shortcoming of the article was that it only included one figure from the journal article. The figure Yirka used was a figure from the supporting information that shows how much light is blocked from the earth’s surface by aerosols. This felt like a very specific part of the journal article to dedicate as the only figure in the news article. I feel like the best figure to include would have been either Figure 1D, which shows the average temperature anomalies during the 2014, 2015, and 2019 warm blobs, or Figure 3C, which indicates that the CMIP6 model more accurately predicts the warm blobs than CMIP5.
Some specific things that the article omitted were the details on how the authors attributed warming sea surface temperatures in the NEP to aerosol reductions rather than other factors, such as GHG emissions, El Niño conditions, and internal forcings. However, I feel like adding these details could lose some readers’ attention, and might make the article too methods-heavy for a general audience. So, I agree with Yirka’s decision to leave these details out.
Overall, I think that the news article did a great job of agreeing with the journal article as well as describing the atmospheric mechanisms and model results in a way that is easy for many readers to understand. While the figure chosen by Yirka seemed a bit too specific for the news article, I still think that the overall accessibility, accuracy, and conciseness of the article deserves a 9/10.
Out of all the news articles I have read so far this semester, I think this one has been the best. It links the original paper, displays a relevant figure in the beginning, and provides context as needed throughout the article. I agree that the methodology is explained well and in simple terms, and I think we are apt to want more written about research reported in a summary article when it is complex and nuanced. I was surprised at how much information was conveyed in such a short article.
ReplyDeleteYirka included a hyperlink in the text "climate models" that grouped articles with climate models together, but it also gave the definition of climate models with some examples. While the examples were not exhaustive, I felt that at least an attempt was made to help clarify any confusion as to what climate models might mean to someone who is not in the field. Several other terms in the article have this feature. If you were unsure what global warming was, there is a similar link to other articles and a definition. This made me feel that the website was actually interested in educating its audience instead of disseminating a particular narrative or opinion.
This is a little bit off-topic, but I was expecting the article to use the term "warm blobs" when it was actually in the article from the National Academy of Sciences. I spent 20 minutes looking up the blob that formed in 2013. I wish scientists could name things in a more intriguing way, like The Blob™.
I second The Blob™
DeleteAlthough I didn't discuss them in my original post, I agree that they hyperlinks were really helpful! I think this is strong evidence that this source is fairly credible and its goals are geared towards education rather than getting clicks. Overall, I think those add a lot to a news article with a wider audience because those with more knowledge on a topic don't need that extra definition and can skip over the hyperlink, while those with less experience can read more about any term they're unfamiliar with.
DeleteAlso, I do really love The Blob™ as a new technical term.
The article is very concise but includes all the necessary information from the study. It has a link to the paper, good figures, background knowledge, methods, and discussions are nicely covered. I think the journal itself targets a more specific group of audiences that has some background in science, and this does a great job building up on the basics and explaining specific ideas in simple terms such as aerosols and mirrors. They also linked each term so that the audiences could have easier access to selected topics of interest. Overall, this one has a good balance between technical terms and general understanding, providing easy access to those who don't know much while providing the resources for them to learn more through citations at the end for "further reading" and hyperlinks in the article.
ReplyDeleteAgreed! The article was one of the best we've seen, in my opinion. This news source seems to be one that exclusively covers topics in science and technology, so I feel like it's a safe assumption that most readers are at least somewhat familiar with current science news and are able to read through these articles with some ease. But I agree that the hyperlinks and references are really useful for someone that may not be familiar with a particular topic or want to learn more about the article.
DeleteI agree with Genevieve that this is probably the best article I've read this semester. You make a specific point that the news article only includes one figure from the journal article and that this was the main detraction (Considering how well it did on all other fronts) and point out a couple figures you would have liked to see, how many of an article's figures (Either by percent or just number) do you think are needed to fully convey the message? I ask because my article did not include any figures from the publication, but I didn't think it was at all necessary, and if anything not including figures was beneficial to the article because most readers would not have understood the figures without significant discussion. I do think the figures you have selected would be good, but I wonder how easily they can be digested by the reader even with the legends/scales and some discussion.
ReplyDeleteThat's a good point. My comment on the figure included in the news article was really just to highlight that a figure from the SI might not always be the most relevant, but I didn't give much thought to how excluding figures all together would have affected the accessibility of the article. I think that with this news source, which focuses on news in science and technology, it would be beneficial to include one or two easily digestible figures, since most readers are used to looking at figures in journal articles. However, for some news sources that we've seen this semester, I feel like adding a figure could take away from the article and distract readers who may try to interpret it and potentially get confused or misled (depending on the intuitiveness of the figure and what it's trying to convey).
DeleteI totally agree that the article does a great job summarizing the journal article so concisely. I really appreciate that there was not any fluff. The news article stayed on topic and focused solely on the findings of the journal article. After reading so many of the other news articles it is refreshing to see this article stick to the specific findings from this one study and not add details from other scientists or researchers. I agree with Theo that a lot of the articles didn't have figures from the journal articles. But I really liked a lot of the figures in the journal article. They were really easy to understand and visually very appealing. So I do think adding a graph would have made the article even better.
ReplyDeleteAgreed! I think that the article did a great job of keeping it concise while also being really accessible to a wide audience, which is a hard thing to balance. I also agree that it's interesting that the article doesn't bring in any other perspectives and only focuses on the content of the journal article. I do enjoy when other articles have done that in the past, and I think the author could have done it in this case if the article were longer.
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