# Tag Info

## Hot answers tagged ozone

15

The sequence of events you describe has never happened, for several reasons. As Sabre Tooth mentions in the comments, vehicle emissions have a negligible effect on stratospheric ozone. (Note that while vehicle emissions can lead to ozone production at ground level, the ozone layer is several kilometres above the Earth's surface and isn't really affected by ...

14

Ozone does not "filter" UV, it absorbs UV radiation (and undergoes some photo-chemistry reactions in the process). By absorbing those wavelengths it prevents them from reaching us at the surface, but cause a temperature rise in the stratosphere. We have plenty of gasses that behave this way for terrestrial radiation (however without the photo-chemical ...

13

$\mathrm{O}_3$ decomposes to $\mathrm{O}_2$. The rate of decomposition increases with temperature. At 20 degrees C, the half-life is about 3 days in air. $\mathrm{NO}$ can catalyze the formation and decomposition of ozone.

12

Hurricanes can be viewed as having primary and secondary circulations. The primary circulation is what we see in satellite photos, comprising the winds and clouds that circle the low pressure zone at the center of the hurricane. The secondary circulation is a vast heat engine that provides the energy needed to sustain the primary circulation. The low ...

10

Really, it is impossible to know how long ozone will persist in the troposphere without knowing what the other chemical concentrations (e.g. CO, NOx, HOx) are and what your photolysis rates are (is it night? cloudy? what latitude? how many hours of sunshine?). Ozone is constantly cycling in the presence of sunlight, so if you are concerned about total ...

8

Two significant factors that influence the size of the ozone hole over the southern pole are temperature and the polar vortex. A number of sources confirm that the ozone hole increases in size when the temperature over Antarctica is colder. (Parrondo et al, The Ozone Hole, Sam Houston State University), The polar vortices that form over the northern and ...

8

Polar stratospheric clouds are the answer. These clouds contain solid nitric acid (mixed with water ice and sulfuric acid), and when they form they remove gaseous nitric acid from the air. This impacts the other chemical cycles in the stratosphere and leads to ozone depletion. This powerpoint is kinda long, but I think it explains the chemistry fairly well. ...

7

I think a brief explanation of how the greenhouse effect1 works is in order here. The light coming from the sun has a broad spectrum, which has its peak roughly in the middle of the range that we see as visible light. This is probably not a coincidence - it's likely that our eyes evolved to use this part of the spectrum because it's the most abundant in ...

7

To summarize David's great answer for folks perhaps looking for an answer more approachable to a wider audience: the answer is a thorough yes to the main question. Hurricanes do have a cooling impact. Hurricanes take warm air near sea level (and evaporated moisture, which is also a form of energy) and release it higher in the atmosphere where it is cooler (...

6

I think it is important to keep in mind the mechanisms that form PM$_{2.5}$ are different than the mechanisms that form O$_3$. From the data your provided you can draw some simple conclusions: Increasing SO$_2$ increases PM$_{2.5}$ Increasing NO$_2$ increases PM$_{2.5}$ Increasing NO$_2$ doesn't necessarily increase O$_{3}$ The last point is what you ...

5

Yes high ozone levels are bad for human health and plant development. Integral to your question is the natural high ozone concentrations at altitudes where you are near the tropopause. The stratosphere has a lot of ozone and it gets entrained to the air around high elevation mountains quite often. You could read what the US EPA has to say about ground ...

5

Typically temperature reductions in localized regions are not due to reduction of greenhouse gases. Greenhouse gases are well mixed and long lived and so reducing their concentrations has more of a regional or global affect. For a "tageted area" you would want to introduce aerosols into the atmosphere (e.g. clouds) so that the incoming light is reflected ...

5

I could find a relatively recent review by Mills et al. (2007) that lists sensitivity to ozone for several crops. Among the most sensitive were (table 1) Watermelons (albeit with very few data points used) Pulses Cotton Wheat While the most resistant crops were Barley Fruits (Plums and Strawberries) Broccoli The measure for ozone used in this review is ...

5

So if you have a mass-mixing ratio, you effectively $\frac{ \text{kg pollutant}}{\text{kg dry air}}$. PPBV is parts per billion volume, or number of molecules of pollutant per billion molecules of dry air. Since not all particles weigh the same, you must use a conversion factor. Consider molar mass, which is the ratio of moles (a unit describing the number ...

5

Let's first consider the scenario in the absence of free radicals that can act as catalysts of $O_3$ destruction. In such scenario, added to the absence of UV radiation, the photolysis of ozone ($O_3 + UV → O_2 + O$) would not be possible. Therefore, the only way to destroy ozone would be by the reaction $O_3 + O· → 2 O_2$ But the lack of UV radiation ...

4

Ozone is most closely correlated to temperature. Yes you need NOx and VOCs to create ozone, but you also need enough photolysis driven by sunlight in order for ozone to form. The day analyzed in the question is during the middle of winter, which generally does not have enough sunlight to allow ozone to build up in the atmosphere. Furthermore, when there ...

4

The south pole has a continent covering it, which allows the retention of relatively long and cold storms, compared to the North Pole. The north pole is covered by water and is not an elevated land mass, so it is a bit warmer on average. Polar stratospheric clouds have chemistry on the ice particles that leads to catalytic ozone depletion (mainly caused by ...

4

Ozone is indeed a greenhouse gas. But not due to its capacity to absorb/scatter UV radiation, but instead due to its capacity to absorb infrared radiation. In contrast with other greenhouse gases (Like $CO_2$ or Methane), the spectral absorption bands of Ozone are not confined to the infrared part of the spectrum, there are ozone absorption bands also the UV ...

3

The calculation of UV indices requires some effort. Because different wavelengths of UV radiation have different effects on skin, to calculate the UV index you need to apply "McKinlay-Diffey" weighting factors to various wavelength components of UV radiation and then integrate (sum) those results and then divide by 25. The procedure does not use ozone ...

3

Regarding linking population density with cases of melanoma, that causal link occurs with all diseases. Cases don't occur where people don't live, they occur where people do live. Consequently, the likelihood of cases occurring increases with population density. UV C radiation is blocked by nitrogen in the upper atmosphere. Upper atmospheric ozone acts as a ...

3

I cannot address your specific questions, but with regards to cancer, Cedric Garland has analyzed and presented similar data and attributed a lower incidence of cancer with a higher production of vitamin D at the lower latitudes as a possible reason. Mina Bissel at Berkeley labs and others have discovered that cells in isolation can lead to cancer. The other ...

3

As bon noted in the comments, that it the time it would take the gamma rays to reach Earth. Gamme rays travel at the same speed as all other forms of electromagnetic radiation, including visible light, so we will not have any warning. This kind of makes the "6000" number meaningless. We will know that the star exploded and the gamme rays will reach earth at ...

3

Tropospheric (near the surface) ozone is a powerful greenhouse gas, even in trace amounts. Strataspheric ozone or the ozone layer is opaque to UV rays coming in and it's opaque to IR rays going out so it has both warming and cooling effects. The net effect of a thickening of the ozone layer is a small warming (with some uncertainty), so the ozone layer is ...

2

Ozone protects us by absorbing ultraviolet radiation As shown in this Chemistry.SE answer, ozone breaks upon incidence of various energies of UV radiation to form oxygen, which itself is somewhat effective at blocking UV radiation at other energies. THe key is that the incident UV radiation transfers its energy to the reaction products in order to break the ...

2

Since ozone is a greenhouse gas, I would say it would enhance warming. This article explains how regional climate may be impacted by ozone This article says that while global ozone should decrease as a result of warming, ozone over populated areas should increase. Water vapor plays a minute role in the production of tropospheric ozone- it increases the ...

2

This is only to address the title question. You are right, in a way. I would recommend that you set an if statement up such that if cos(sza)>=0: raw_uvi = 12.50*pow(cos(sza),2.42)*pow(float(ozone)/300,-1.23) else: raw_uvi=0.0 This makes it so that when the sun is beneath the horizon, the sun is not 'taking back' the energy

2

Ozone can indeed absorb UV and infrared radiation. The UV part, plays an important role in protecting us from harmful radiation, and the infrared part makes it an effective greenhouse gas. All gases absorb/emit radiation at multiple different and discrete wavelengths. That's know since the early 19th century when the Fraunhofer lines where observed. The ...

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