[OC] Eine Satellitenkarte der atmosphärischen Verschiebung, die über den Städten Nordamerikas stattfindet

„highly oxidized compounds and contribute to secondary organic aerosol.“

What does this mean? With no background in these chemicals I don’t understand why it matters that NY and Chicago ‚produced highly oxidized compounds‘ or that they ‚contribute to secondary organic aerosol.‘

But what does it mean?

>Over the past few decades, NOₓ emissions have fallen across much of North America. As a result, the chemistry of many cities is changing. The study found that New York, Chicago, and Toronto have substantially longer RO₂ lifetimes than Los Angeles, giving these radicals more time to undergo reactions that can produce highly oxidized compounds and contribute to secondary organic aerosol.

Is it good or bad that those cities are producing „highly oxidized compounds and contribute to secondary organic aerosol“? Why?

I’m pretty sure the difference in the two sides is from GOES-E vs GOES-W, right? What’s the adjustment between the two halves of the map?

This is what chat gpt had to say about it for anyone still scratching their heads

ELI5 version:

Imagine the air over a city is like a giant chemistry lab.
**RO₂ radicals** are tiny, hyperactive chemical “workers” created when sunlight hits pollution from cars, factories, trees, and other sources.

These workers don’t live very long. They run around looking for something to react with.
**NOₓ** (pollution mainly from vehicle exhaust and combustion) is one of their favorite things to react with.
Years ago, cities had lots of NOₓ, so RO₂ workers would quickly bump into NOₓ and react. That means they had **short lifetimes** (they didn’t survive long).

Today, many cities have cleaned up NOₓ pollution, so the RO₂ workers spend more time wandering around before finding something to react with. That means they have **longer lifetimes**.

**Why does that matter?**

Think of RO₂ radicals as ingredients in a recipe.
If they react with NOₓ immediately, they help make **ground-level ozone** (the bad kind that irritates lungs).
If they stick around longer, they can participate in other reactions and help create tiny airborne particles called **secondary organic aerosols** (a major component of smog and haze).

So as NOₓ pollution decreases, the atmosphere doesn’t simply become “less chemical.” Instead, the chemistry changes direction.

**What the map is showing**

**Purple areas** = RO₂ radicals disappear quickly (lots of opportunities to react).

**Green/blue areas** = RO₂ radicals survive longer before reacting.

The study found that cities like:

New York City
Chicago
Toronto

have longer RO₂ lifetimes than:

Los Angeles

This suggests the air chemistry in those cities is shifting toward different reaction pathways.

**The big takeaway**

Scientists expected cleaner air when NOₓ emissions dropped, and that has happened in many ways. But the atmosphere is a complicated chemistry system.

The surprising finding is:

As NOₓ pollution falls, many cities across North America are entering a new chemical regime where RO₂ radicals live longer and produce different pollutants than they used to.

So the map is essentially showing **where urban air chemistry is changing the most**, not necessarily where the air is best or worst. It’s a picture of how the atmosphere’s “recipe book” is being rewritten as emissions change.

There’s clearly two datasets stitched together here, and poorly. How can you claim the data on LA and the east coast are so different when the baseline reading in LA is so much lower? Or did you just stuff caltech data into an ai and apply zero critical thinking?

Am I missing something or is the clear artifact not addressed?

The attached figure is a measurement of RO2 lifetime, not delta lifetime. The imagine suggests that there is an approximate 5s shift in lifetime uniformly across the Dakotas?

Initially I thought that the data was a time comparison from 1 time point in the west, and a different time point on the east. However, if you look at the Dakotas region there is no clear boundary between the measurements. This suggests that the data is spatially averaged and likely detected through two different sources which have unique calibration curves or detection equipment.

Additionally the data presented suggests that the northeast has a unique atmosphere chemistry compared to the entire U.S. west. With no discussion regarding how come that might be the case.

before we accept your data perhaps you’d like to explain why is there a straight line down the middle of the map?

This thread is really eye opening for the way many people form opinions today. So many people just asking you to plainly tell them if the map should make them feel good or bad. Same way so many people get their opinions on media, news, and politics it seems.

I don’t understand the implications of this map either. But everything doesn’t have to boil down to good / bad. Nuance and ambiguity might be dead. Condolences to OP for just trying to share their work without having to give some conclusive, definitive statement to go along with it.

So we traded one air pollunent for another, ~sigh.

So by reducing air pollution, we are unintentionally increasing air pollution?

Given that this is for summer 2023 and we had a gigantic wildfire season and air quality (fine particulate and ozone) was out of whack for a long period of time, could that have any impact on this map of RO2?

Girl get outta here with this crap map