Talk:Wet-bulb temperature

message: This article was automatically assessed because at least one WikiProject had rated the article as stub, and the rating on other projects was brought up to Stub class. BetacommandBot 10:05, 10 November 2007 (UTC)
thread_title:  WikiProject class rating

message: The term "isobaric wet-bulb" seems to be used mostly by meteorologists.
*http://www.google.com/search?q=%22isobaric+wet-bulb+temperature%22
:Results 1 - 10 of about 134 for "isobaric wet-bulb temperature"
The term "thermodynamic wet-bulb" seems to be more popular:
*http://www.google.com/search?q=%22thermodynamic+wet-bulb+temperature%22
:Results 1 - 10 of about 894 for "thermodynamic wet-bulb temperature".
-Ac44ck (talk) 22:26, 7 April 2008 (UTC)
thread_title:  Changed isobaric to thermodynamic 

message: Dr. Eric A Anderson (1968) gives an equation for estimating wetbulb temperature (Tw) from drybulb (T) and dewpoint (Td) temperatures, all in degrees F:
Tw = T - (T - Td)*(0.12 + 0.008*T)
source link: http://snow.ag.uidaho.edu/Climate/Reference_materials/Atmos_formulas.html  —Preceding unsigned comment added by 199.46.245.232 (talk) 20:04, 7 May 2008 (UTC)
thread_title: Tw as a function of T and Td

message: "Wet-bulb temperatures are computed based on empirical equations derived by Julius F Bosen and revised by J. N. Johnson in Naval Weather Service Technical Note #7 (1963). Temperatures must be input in degrees Fahrenheit.
For Fahrenheit temperatures equal to or greater than 0-degrees;
TW = T - (0.034A - 0.00072AB)*(T + TD - 2D + 108)
For Fahrenheit temperatures below 0-degrees;
TW = T - (0.034A - 0.006A2)*(0.6(T - TD) - 2D + 108)
where: T = dry-bulb temperature, degrees-F; TD = dew-point temperature, degrees-F; A = (T - TD)/10; B = (A - 1); D = P/33.8639; P = pressure in mb."
source link: http://dlaweb.whoi.edu/lightship/lightships_meta_data_td1129.html  —Preceding unsigned comment added by 199.46.245.232 (talk) 21:07, 21 November 2008 (UTC)
thread_title: Empirical Tw equations derived by late Julius F Bosen

message: *Do we want to show how to calculate dew point temperature in an article on wet bulb temperature?
*The formula seems overly complex. Is it calculating the dew point temperature at sea level as opposed to at the measuring station? That value may be useful on a national weather map, but it may not be the value usually sought. 
*Shouldn't e_w be "wet-bulb at station pressure" and not "wet-bulb at saturation pressure"?
-Ac44ck (talk) 01:58, 21 December 2008 (UTC)
replies: text: I moved it to the article on dew point temperature. -Ac44ck (talk) 19:38, 21 December 2008 (UTC)
thread_title:  Formula for dew point temperature 

message: When asked for a definition of Wet Bulb Temperature I quoted from the article: "the temperature a volume of air would have if cooled adiabatically to saturation at constant pressure by evaporation of water into it, all latent heat being supplied by the volume of air."
Unfortunately the professor of atmospheric physics didn't agree and gave the following feedback:
"Evaporating water into the air parcel isn't an adiabatic process as it involves heat transfer from air to water. This is a semantic point since the system (water+air) is indeed adiabatic but we use the term adiabatic in atmospheric science to refer to the gaseous part of the atmosphere only."
Perhaps it would be worth making the clarification. Zebas (talk) 14:27, 20 January 2010 (UTC)
thread_title:  Cooling adiabatically to saturation 

message: I think we have resolved the major problems with the sub section on wet bulb temp and human wealth.  The remaining issue is whether to say ANYTHING about the likelihood that this will be an issue EVER.
Option 1:  Say nothing.  That's the current version as I write this.
Option 2:  Use the lead authors quote from the news article which in its entirety is:
:Although we are very unlikely to reach such temperatures this century, they could happen in the next. http://www.sciencedaily.com/releases/2010/05/100504155413.htm
Option 3:  Use the author's text from the peer reviewed literature.  That paragraph in its entirety (minus internal cites) says:
:Recent studies have highlighted the possibility of large global warmings in the absence of strong mitigation measures, for example the possibility of over 7 °C of warming this century alone. Warming will not stop in 2100 if emissions continue. Each doubling of carbon dioxide is expected to produce 1.9–4.5 °C of warming at equilibrium, but this is poorly constrained on the high side and according to one new estimate has a 5% chance of exceeding 7.1 °C per doubling. Because combustion of all available fossil fuels could produce 2.75 doublings of CO2 by 2300, even a 4.5 °C sensitivity could eventually produce 12 °C of warming. Degassing of various natural stores of methane and/or CO2 in a warmer climate could increase warming further. Thus while central estimates of business-as-usual warming by 2100 are 3–4 °C, eventual warmings of 10 °C are quite feasible and even 20 °C is theoretically possible. http://www.pnas.org/content/107/21/9552.full
If you want to include a reference to the authors statements on liklihood, then we should say something that faithfully reports the authors complete statement without altering its meaning by selective truncation.   Or we could just say nothing, which is my current preference for this article. NewsAndEventsGuy (talk) 10:02, 5 June 2011 (UTC)
replies: text: Still looks like a long-winded way to make a plug for global warming to me. Whether atmospheric temperatures rise or not is about ... atmospheric temperature, not "human health." Where and how wet bulb temperature goes "too high" is meteorology, physics or engineering, not health science. In my experience, the global warming crowd is nothing if not tenaciously tendentious. I may revisit this later. As far as I am concerned for now, I have other things to do and this paper (it isn't yours by chance, is it?) gets cite points for having footnotes in Wikipedia. I would still favor omitting the dire forecast and the emphasis on a criterion that no one else uses. - Ac44ck (talk) 09:18, 6 June 2011 (UTC)
thread_title:  Likelihood of environmental conditions approaching wet bulb survival limit 

message: This article is not a suitable venue for speculations about global warming.
This recent edit is out of place:
:although detailed analysis predicts that a large degree of global warming ...
And if a "large degree of global warming" does not happen, then the statement is irrelevant to the thermodynamic property which is the subject of this article.
-Ac44ck (talk) 03:28, 9 July 2012 (UTC)
replies: text: The article currently say "a large degree of global warming can ..." ... this is quite uncontroversial. And while global warming itself is controversial, it is not controversial that a large number of climate scientists -- certainly the most vocal ones -- as well as much of the media, is saying that a large degree of global warming will occur, and a large fraction of the population believes that it will. Since this scenario is well within the realm of possibility, it is perfectly valid to say what the consequences of it would be.
Those who have vociferously objected that the language isn't neutral have had over a year to repair it but have not done so. As there does not appear anywhere on this page a valid argument that this section violates neutrality nor a coherent suggestion to add material to make it neutral (only calls to remove mention of global warming by people who are clearly ideologically opposed to it), I'm removing the tag. -- 96.248.226.133 (talk) 23:18, 10 January 2013 (UTC)
replies: text: It isn't appropriate to fix something that doesn't belong. It should simply go away. - Ac44ck (talk) 05:16, 24 July 2014 (UTC)
thread_title:  Global Warming 

message: I just noticed some idiot wanting attention vandalized "temperature" to "shitty"..  I reverted it, but..  there may be other hidden vandalism - can someone who's worked with this article look it over to make sure I didn't miss anything? Thanks, Jimw338 (talk) 23:52, 11 June 2013 (UTC)
thread_title:  Vandalism -  Jun 11 2013 

message: 1) Cooling of the human body through perspiration is inhibited as the wet-bulb temperature (and absolute humidity) of the surrounding air increases in summer.
Good point but should be said mire directly: presumably what is meant is that the wet-bulb temperature  is considered  a better measure of discomfort than either the dry-bulb temp or the relative humidity alone. But I don't have a source for this.
2) Other mechanisms may be at work in winter if there is validity to the notion of a "humid" or "damp cold." 
I appreciate the curiosity about this point (since "damp chill" will not caused by evaporative cooling, could it be by enhanced heat conduction?) but this sounds like a private opinion or a call for research.
3) Lower wet-bulb temperatures that correspond with drier air in summer can translate to energy savings in air-conditioned buildings due to:
Reduced dehumidification load for ventilation air
Increased efficiency of cooling towers
Interesting but perhaps belongs later in the article? 84.227.241.146 (talk) 16:42, 13 September 2014 (UTC)
replies: text: Okay, looking around the web I can see the crucial difference between typical high dry-bulb and wet-bulb temperatures and their effects on humans. But 3) and 4) should come only after presentation of that essential information. 84.227.241.146 (talk) 16:57, 13 September 2014 (UTC)
thread_title:  Comment on "General" Section 

message: The link marked "Indirect evaporative cooler cools below wet-bulb" seems interesting and relavant, but it appears to be broken.  Does anyone know where this should point? --Aj537 (talk) 15:50, 1 May 2015 (UTC)
thread_title:  External links 

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thread_title:  External links modified 

message: The section "Heat waves with high humidity" references "the highest heat index ever recorded" having occurred in Dhahran, Saudi Arabia, but does not state what wet bulb temperature this heat index corresponds to. I think that in an article about wet bulb temperature it is germane to tell what is the highest wet-bulb temperature observed on Earth. While also the source fails to state the wet-bulb temperature, it does supply the dry-bulb and dew-point temperatures from which the wet-bulb temperature can readily be calculated. 
The temperatures cited are 46 and 35 degrees Celsius respectively. The saturation water vapor pressures at those temperatures are 8197.19 Pa and 5620.54 Pa respectively, giving a relative humidity of 68.57%. I have calculated the pressures using the Goff-Gratch (1946) equation as given in the Wikipedia article. Next, using the formula in the article Roland B. Stull: "Wet-Bulb Temperature from Relative Humidity and Air Temperature" (American Meteorological Society 2011, DOI: 10.1175/JAMC-D-11-0143.1; https://open.library.ubc.ca/cIRcle/collections/facultyresearchandpublications/52383/items/1.0041967), I arrive at the wet-bulb temperature of 36.5 degrees Celsius. 
(If the source is correct, this is quite remarkable as such conditions are not humanly survivable beyond a few hours.)
Does this computation constitute "original research"? Can this figure, a wet-bulb temperature of 36.5 degrees Celsius, be included in the article without any further sources? Or could the article say something along the following lines?
*In 2003, Dhahran, Saudi Arabia, saw the highest heat index ever recorded at  with a temperature of  and a   dew point. This corresponds to a wet-bulb temperature of  (calculated using the empirical equation given by Roland B. Stull Roland B. Stull: Wet-Bulb Temperature from Relative Humidity and Air Temperature, Journal of Applied Meteorology and Climatology, November 2011, p. 2267 after using the Goff-Gratch (1946) equation to compute the partial pressures for the relative humidity).
Cacadril (talk) 00:51, 7 October 2019 (UTC)
thread_title:  Translate historical maximum from heat index to  wet bulb temperature 

message: The last paragraph of the introduction needs work. I'm loath to mess with it, since this subject is way out of my expertise.
The first issue is that the concept of heat index is introduced without explanation. Yes, a link is provided, but it seems to me that the relationship between the two concepts — wet-bulb temperature and heat index — needs to be clarified within this article, without requiring the reader to go off to the heat index article. Both concepts (if I understand correctly) combine temperature and humidity, but in different ways, and somewhere in this article that ought to be spelled out, with illustrative examples. I imagine an entire short section could be devoted to this relationship. Is it true that the wet-bulb temperature determines the heat index and vice versa? If so, what are the formulas or rules?
And why is the concept of heat index brought up in the introduction, rather than in the body? Can't one get the correct idea of wet-bulb temperature without using this undefined phrase?
The second issue is in the sentence "The theoretical limit to human survival... is 35 °C." Is that a wet-bulb temperature? I presume so, and if so it should be made explicit. If not, then why is it mentioned? Again this sentence brings up heat index — and the remark that it's only a "theoretical" equivalence is baffling. Ishboyfay (talk) 23:30, 29 June 2021 (UTC)
thread_title:  Last paragraph of intro needs to be improved