Talk:Outgoing longwave radiation

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2019 and 9 April 2019. Further details are available on the course page. Student editor(s): Oliviae1398.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 05:56, 17 January 2022 (UTC)

Bibliography

Xie, PingPing. "Global Monthly Precipitation Estimates from Satellite-Observed Outgoing Longwave Radiation". journals.ametsoc.org. doi:10.1175/1520-0442(1998)011%3C0137:gmpefs%3E2.0.co;2. Retrieved 2019-02-17.

Randall, David. "Relationship between the Longwave Cloud Radiative Forcing at the Surface and the Top of the Atmosphere". journals.ametsoc.org. doi:10.1175/1520-0442(1990)003%3C1435:rbtlcr%3E2.0.co;2. Retrieved 2019-02-17.

Harries, John (March 2001). "Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997". Nature. 410: 355–357.

Oliviae1398 (talk) 04:07, 17 February 2019 (UTC)

Importance

I have rated this article as having HIGH importance for WikiProject:Environment, because the amount of outgoing long-wave radiation from the atmosphere is a key quantity in the energy balance of the Earth, and hence forms the central pillar of the theory of anthropogenic climate change. This article needs to be fleshed out with details, on an urgent basis. —Aetheling (talk) 19:02, 28 January 2014 (UTC)

Rename to Longwave radiation

Since longwave radiation can bounce back to the surface, for instance because of cloud cover, i assume we should rename the article to just "longwave radiation". prokaryotes (talk) 21:58, 31 July 2014 (UTC)

Requested move 31 July 2014

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: not moved. Longwave radiation retargeted to point to Longwave (disambiguation). Jenks24 (talk) 13:12, 8 August 2014 (UTC)

---

Outgoing longwave radiation → Longwave radiation – Longwave radiation does not necessarily "moves out", since it can be reflected back to the surface layers by clouds. – prokaryotes (talk) 22:35, 31 July 2014 (UTC)

This is a contested technical request (permalink). EdJohnston (talk) 23:25, 31 July 2014 (UTC)

• Oppose: Sources, for instance NOAA, do call it Outgoing Longwave Radiation. EdJohnston (talk) 23:25, 31 July 2014 (UTC)

EdJohnston, currently "Longwave radiation" links to this page, i rather have the page renamed/moved as suggested and subsequently adding a section on OLR, than to create another article. And see this Google scholar search, for the term, which depending on the measurements or specific topic discusses various longwave scenarios, http://scholar.google.com/scholar?hl=en&q=Longwave+radiation&btnG=&as_sdt=1%2C5&as_sdtp= or see this article, explaining different longwaves http://www.skepticalscience.com/print.php?r=35 or see this scholar search for downward longwave radiation http://scholar.google.com/scholar?q=downward+longwave+radiation&btnG=&hl=en&as_sdt=0%2C5 So what do you suggest? prokaryotes (talk) 00:43, 1 August 2014 (UTC)

The sources you provide seem to treat Outgoing Longwave Radiation as the net quantity of what goes into space (i.e. not including anything that bounces off the clouds and goes back to earth). Why not prepare a draft of some new material on the article talk page. Show how you would explain Outgoing Longwave Radiation and Longwave Radiation in the same article. If others support this idea, the article text could be updated. See also the article on Earth's energy budget which could be a better place for explaining Longwave Radiation. EdJohnston (talk) 01:42, 1 August 2014 (UTC)

Thanks for your input, i will extend the part over at EEB first and prepare something for this page. But if we change it i believe it would make sense to rename the article, or just create a separate page. Maybe other editors have some suggestions too. Generally, longwave radiation is important to understand current changes of the climate, for instance precipitation changes (increasing) and related heat fluxes. prokaryotes (talk) 01:59, 1 August 2014 (UTC)

• Strong Oppose Longwave radiation is RF-radiation. "longwave radiation" should NOT redirect here. It's a radio-frequency band, and we have a frequency article for it. Same as microwave radiation being composed of microwaves, longwave radiation is composed of longwaves. Retarget "longwave radiation" to Longwave. -- 65.94.169.222 (talk) 08:27, 3 August 2014 (UTC)

Good point. Retargeting longwave radiation would resolve this move request. However, the longwave article is primarily about radio transmissions. Thus, i rather have longwave radiation become an article too. prokaryotes (talk) 10:30, 3 August 2014 (UTC)

• Strong oppose per the above. However the phrase "longwave radiation" is ambiguous. It might refer to long wave RF (its original and better-known meaning) or it might refer to OLR phenomena which, in general, have a much shorter wavelength. I'd suggest that Longwave radiation be redirected to Longwave (disambiguation). — Cheers, Steelpillow (Talk) 13:49, 3 August 2014 (UTC)

• Oppose. As others have said, "longwave radiation" could mean RF or OLR. Redirect to Longwave (disambiguation). --Harumphy (talk) 18:25, 3 August 2014 (UTC)

• Question -- In "outgoing longwave radiation", is the word "longwave" short for "longwave infrared" (LWIR) (around 8-13 micron wavelength)? Or does OLR include the whole infrared spectrum? --Steve (talk) 22:07, 3 August 2014 (UTC)

---

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

The wavelength of infrared radiation is dependant of the radiation-surface-temperature calculated by the Wien's displacement law:

LambdaMax = 2897.8 um K / Temperature

or 

Temperature = 2897.8 um K / LambdaMax

Here are some calculated values: LambdaMax: Temperature: 7 um 414 K / 141°C / 286°F 10 um 290 K /17°C / 62°F 13 um 223 K / -50°C / -58°F 15 um 193 K / 80°C / -112.3°F 15.75 um 184 K / -89.2°C / -128.5°F

The coolest temperature on earth ever measured was in the antarctis at 184K (-89.2°C/-128.5°F) on july 21st 1983.

So what does all these calculated values mean? ... well ... the infrared transparency window of the earth's atmosphere is between 7 um and 13 um. This in consequence means, that all infrared radiation emitted by the earth's surface at temperatures between -58°F (223K/-50°C) and 286°F (414K/141°C) leaves undisturbed by any elements of the atmosphere into space! In a way the CO2 absorption wavelength is out-of-range with 15 um! That on the contrary means, that there cannot be any so called "backradiation" which usually gets blaimed for the so called greenhouse effect is NOT REAL ! It is scientific fiction! The only place on earth where theoretical CO2 might absorb any infrared radiation at 15 um might be the area of the antarctis ... the only place where it could theoretically be possible to measure any so called "back-radiation"! — Preceding unsigned comment added by 31.18.184.85 (talk) 12:40, 14 March 2019 (UTC)

Global radiation budget - the numbers don't add up?

Copied from refferance desk

I'm referring to a diagram in Outgoing longwave radiation. According to the nice diagram, Earth receives 235 W/m^2 from the sun, and emits back (195+40)=235W/m^2. Thanos would say "Perfectly balanced... as all things should be." Evidently this can not be true since the warming already occurs and is easily measured. What gives? אילן שמעוני (talk) 06:30, 9 October 2019 (UTC)

The surface of Earth is constantly being warmed by the hot interior. Dbfirs 06:35, 9 October 2019 (UTC)

In that case it should have been warming forever. I mean even if all there was no sun to warm Earth up, it would have been (452-235)W/m^2 balance. That doesn't work either. אילן שמעוני (talk) 07:53, 9 October 2019 (UTC)

Geothermal heat only accounts for about 0.09 W/m², according to Earth's internal heat budget. Heating the top 200 meters of the oceans by 0.02 K per year takes about 0.4 W/m², which is much more than the geothermal heat, but still low enough to disappear in the rounding of that 235 W/m² ingoing and outgoing radiation. PiusImpavidus (talk) 09:00, 9 October 2019 (UTC)

The warming is on average about 1 Watt per square meter. It's small enough to get lost in rounding errors on a simplified diagram. Someguy1221 (talk) 09:59, 9 October 2019 (UTC)

OK, makes sense. I suggest, though, that because of the importance of the issue, the diagram must present this 1 W/m^2, either substructing from the output or increasing the input. אילן שמעוני (talk) 11:18, 9 October 2019 (UTC)

The diagram was originally intended and used in other articles to explain the greenhouse effect, i.e. the several hundred W/m^2 recycling of energy. In that context, it is pedagogically helpful to understand that the Earth's surface will be kept warm even when energy flows are in equilibrium. I'm not sure it makes sense to modify the diagram, affecting all the places it is used, in order to represent the current global warming component. Perhaps it is better to use a different diagram in places where one wants to depict the current energy imbalance. Dragons flight (talk) 07:43, 12 October 2019 (UTC)