1 00:00:01,350 --> 00:00:06,490 [Music] 2 00:00:12,680 --> 00:00:09,919 if you want to apply connection to other 3 00:00:15,560 --> 00:00:12,690 planets you need to think of what could 4 00:00:17,390 --> 00:00:15,570 happen if you change the gas involved so 5 00:00:20,000 --> 00:00:17,400 of course as we said we could change the 6 00:00:22,130 --> 00:00:20,010 common table gas but we can also change 7 00:00:26,109 --> 00:00:22,140 for example what is the background gas 8 00:00:29,390 --> 00:00:26,119 hydrogen but then you really don't see 9 00:00:31,550 --> 00:00:29,400 what could happen because basically you 10 00:00:34,389 --> 00:00:31,560 have a gas hydrogen or nitrogen it's 11 00:00:38,420 --> 00:00:34,399 basically the same thing it has the same 12 00:00:42,260 --> 00:00:38,430 it has the same structure it's not 13 00:00:44,330 --> 00:00:42,270 particularly relatively active so what 14 00:00:46,729 --> 00:00:44,340 does what does happen but first what the 15 00:00:48,799 --> 00:00:46,739 why do you care what could happen if you 16 00:00:51,410 --> 00:00:48,809 have conviction in a hydrogen dominated 17 00:00:54,049 --> 00:00:51,420 measure well you can care because as we 18 00:00:58,520 --> 00:00:54,059 saw yesterday it does happen and we do 19 00:01:02,060 --> 00:00:58,530 see it so for example you have the you 20 00:01:04,340 --> 00:01:02,070 have here a cyclone it's an it's on 21 00:01:06,289 --> 00:01:04,350 Jupiter and as we were talking about 22 00:01:08,000 --> 00:01:06,299 convection happening on very different 23 00:01:10,580 --> 00:01:08,010 scales actually here the scale of the 24 00:01:13,250 --> 00:01:10,590 spectrum is the earth okay you could fit 25 00:01:15,530 --> 00:01:13,260 near Earth in there and basically you 26 00:01:17,450 --> 00:01:15,540 see for example here clouds they are not 27 00:01:18,859 --> 00:01:17,460 water cloud the ammonia cloud and you 28 00:01:20,749 --> 00:01:18,869 see that they are actually hi hug 29 00:01:24,190 --> 00:01:20,759 because here or there you can see the 30 00:01:29,270 --> 00:01:24,200 shadow that the cast over the the lower 31 00:01:31,870 --> 00:01:29,280 level gas or clouds so you do have 32 00:01:34,190 --> 00:01:31,880 convection and and you do have very 33 00:01:37,670 --> 00:01:34,200 extreme convection when you look for 34 00:01:40,609 --> 00:01:37,680 example at this which is a well-known 35 00:01:43,249 --> 00:01:40,619 photograph of the the Saturn great white 36 00:01:46,460 --> 00:01:43,259 white storm where you actually it's a 37 00:01:49,340 --> 00:01:46,470 couple weeks a month after it began and 38 00:01:51,740 --> 00:01:49,350 then you already see this big storm you 39 00:01:53,929 --> 00:01:51,750 have the wind shear that creates trail 40 00:01:56,929 --> 00:01:53,939 and then the storm has time to actually 41 00:01:59,719 --> 00:01:56,939 circle the trail had time to shape of 42 00:02:03,859 --> 00:01:59,729 the planet and so again the question is 43 00:02:06,080 --> 00:02:03,869 yes but how does how is this couldn't be 44 00:02:09,410 --> 00:02:06,090 different from what we just heard for 45 00:02:13,130 --> 00:02:09,420 earth convection and arid it if you have 46 00:02:15,170 --> 00:02:13,140 earth or or your generic moist planet 47 00:02:16,640 --> 00:02:15,180 that goes as we heard you have your 48 00:02:19,280 --> 00:02:16,650 temperature profile that is going 49 00:02:21,680 --> 00:02:19,290 basically on the moist adiabat where you 50 00:02:25,580 --> 00:02:21,690 have your moist troposphere and you have 51 00:02:28,309 --> 00:02:25,590 your humidity here EQ is what I call the 52 00:02:31,310 --> 00:02:28,319 the specialty community so the amount of 53 00:02:33,199 --> 00:02:31,320 water vapor pair amount of dry air and 54 00:02:36,430 --> 00:02:33,209 medic it goes down because you have to 55 00:02:40,370 --> 00:02:36,440 follow them a thermodynamic flow and so 56 00:02:42,699 --> 00:02:40,380 as it's warmer down there 57 00:02:46,130 --> 00:02:42,709 you have more water vapor and and it's 58 00:02:50,080 --> 00:02:46,140 colder there you have a drier dryer air 59 00:02:52,910 --> 00:02:50,090 and then of course here as we heard 60 00:02:55,310 --> 00:02:52,920 convection is mostly due to thermal 61 00:02:56,570 --> 00:02:55,320 gradient that is caused by radiation so 62 00:02:59,540 --> 00:02:56,580 basically the fact that it's hotter 63 00:03:03,449 --> 00:02:59,550 there but it's also helped by as we 64 00:03:10,530 --> 00:03:03,459 offer also add latent heat book 65 00:03:13,289 --> 00:03:10,540 or about that so it's held by latent 66 00:03:15,149 --> 00:03:13,299 heat but it's also held button by 67 00:03:16,920 --> 00:03:15,159 another process we didn't hear about 68 00:03:18,539 --> 00:03:16,930 which is the fact that you have a 69 00:03:20,940 --> 00:03:18,549 difference in molecular weight so what 70 00:03:24,119 --> 00:03:20,950 is this basically in Earth your 71 00:03:26,429 --> 00:03:24,129 background gas is nitrogen and and then 72 00:03:29,879 --> 00:03:26,439 the the the mean molecular weights the 73 00:03:32,220 --> 00:03:29,889 weight of a molecule of nitrogen is 28 74 00:03:35,429 --> 00:03:32,230 but then the the minimal ocular weight 75 00:03:37,379 --> 00:03:35,439 of water is 18 you have 18 new clients 76 00:03:39,149 --> 00:03:37,389 in in the water molecule and so 77 00:03:41,819 --> 00:03:39,159 basically what it does is that here 78 00:03:43,740 --> 00:03:41,829 because you have more water and that 79 00:03:46,409 --> 00:03:43,750 water is a bit lighter than nitrogen 80 00:03:48,959 --> 00:03:46,419 it's a little bit less dense here then 81 00:03:51,149 --> 00:03:48,969 here and so basically you have another 82 00:03:53,280 --> 00:03:51,159 process helping you because when you 83 00:03:55,289 --> 00:03:53,290 want convection you want hot stuff but 84 00:03:58,229 --> 00:03:55,299 why do you want you we won't let them 85 00:04:00,869 --> 00:03:58,239 stuff so here because you have water you 86 00:04:05,849 --> 00:04:00,879 have blend temps less dense air moist 87 00:04:08,849 --> 00:04:05,859 air that will be helped to get lost so 88 00:04:11,399 --> 00:04:08,859 that's a variant see effect so how does 89 00:04:14,960 --> 00:04:11,409 it change when you go to a jump and for 90 00:04:17,550 --> 00:04:14,970 ample so the the most important one one 91 00:04:19,409 --> 00:04:17,560 change is basically that you don't have 92 00:04:21,539 --> 00:04:19,419 a surface but that doesn't change too 93 00:04:24,540 --> 00:04:21,549 much so what basically happens is that 94 00:04:27,899 --> 00:04:24,550 in your atmosphere in your planet you 95 00:04:31,770 --> 00:04:27,909 have some deep abundance of your oxygen 96 00:04:33,870 --> 00:04:31,780 or in so basically of your water and so 97 00:04:36,330 --> 00:04:33,880 basically what happens is that you still 98 00:04:40,230 --> 00:04:36,340 at your moist rodebush here and you have 99 00:04:41,999 --> 00:04:40,240 your water vapor to saturation that is 100 00:04:44,670 --> 00:04:42,009 trying to follow the determined 101 00:04:49,140 --> 00:04:44,680 dynamical law and at some point it hits 102 00:04:51,029 --> 00:04:49,150 the the value of your deep interior and 103 00:04:53,100 --> 00:04:51,039 then you cannot you can't have more 104 00:04:57,149 --> 00:04:53,110 water than that and so basically here 105 00:04:59,969 --> 00:04:57,159 water stops to condense so you just have 106 00:05:03,210 --> 00:04:59,979 a constant or multi constant amount of 107 00:05:06,089 --> 00:05:03,220 water then you have a dry troposphere so 108 00:05:09,719 --> 00:05:06,099 now the lapse rate is not a most lapse 109 00:05:11,430 --> 00:05:09,729 rate but a dry lapse rate and here that 110 00:05:13,469 --> 00:05:11,440 pretty easy because that's where you 111 00:05:15,709 --> 00:05:13,479 would expect clouds to be because you 112 00:05:17,320 --> 00:05:15,719 can't have clouds down below the clouds 113 00:05:20,110 --> 00:05:17,330 particles the 114 00:05:22,149 --> 00:05:20,120 not easy to laugh too much too much 115 00:05:24,670 --> 00:05:22,159 higher than this but basically the deck 116 00:05:27,279 --> 00:05:24,680 you you should have a deck of clouds 117 00:05:29,230 --> 00:05:27,289 pretty much at this level of transition 118 00:05:32,200 --> 00:05:29,240 between the dry and the moisture of the 119 00:05:34,659 --> 00:05:32,210 sphere but what is really really 120 00:05:36,820 --> 00:05:34,669 different is that whereas in Earth we 121 00:05:39,159 --> 00:05:36,830 had a profile profile of mini molecular 122 00:05:41,830 --> 00:05:39,169 weight like that now we don't have em 123 00:05:44,980 --> 00:05:41,840 too as a background gas we have we have 124 00:05:47,920 --> 00:05:44,990 H 2 and H 2 as a minimal ocular weight 125 00:05:51,909 --> 00:05:47,930 of 2 it's tiny it's not a fraction 126 00:05:54,730 --> 00:05:51,919 higher than water it's 10 times lower 127 00:05:57,999 --> 00:05:54,740 than water so actually you can have a 128 00:06:00,520 --> 00:05:58,009 huge huge gradient of min molecular 129 00:06:03,189 --> 00:06:00,530 weight but as you so the minimal acrylic 130 00:06:06,520 --> 00:06:03,199 gradient is not the same way as before 131 00:06:09,850 --> 00:06:06,530 here you have lighter water for gas on 132 00:06:11,559 --> 00:06:09,860 top of heavier water rich gas so you 133 00:06:14,379 --> 00:06:11,569 have a problem because you have again a 134 00:06:17,140 --> 00:06:14,389 battle or competition because you have a 135 00:06:21,010 --> 00:06:17,150 competition between your radiation that 136 00:06:24,700 --> 00:06:21,020 wants actually you to come back and this 137 00:06:27,279 --> 00:06:24,710 process that tries not that tries to 138 00:06:32,110 --> 00:06:27,289 suppress that convection so how do you 139 00:06:33,869 --> 00:06:32,120 how can we actually quantify that so 140 00:06:37,990 --> 00:06:33,879 basically you can come back to your 141 00:06:40,719 --> 00:06:38,000 convection 1 1 and and try to understand 142 00:06:43,659 --> 00:06:40,729 first what would be the convection 143 00:06:46,089 --> 00:06:43,669 pattern in a dry atmosphere I'm actually 144 00:06:48,309 --> 00:06:46,099 basically this is this you have your 145 00:06:50,920 --> 00:06:48,319 density in the atmosphere as a function 146 00:06:53,529 --> 00:06:50,930 of height and here the dotted line is 147 00:06:55,779 --> 00:06:53,539 the the density profile that you would 148 00:07:00,369 --> 00:06:55,789 have in your atmosphere with some 149 00:07:02,920 --> 00:07:00,379 thermal gradient nabrit and then you 150 00:07:06,519 --> 00:07:02,930 have your adiabatic gradient this is the 151 00:07:08,769 --> 00:07:06,529 gradient of density that a particle 152 00:07:10,839 --> 00:07:08,779 would follow if it were moved in the 153 00:07:13,499 --> 00:07:10,849 atmosphere adiabatically so without any 154 00:07:17,050 --> 00:07:13,509 exchange of heat so let's try to have a 155 00:07:20,619 --> 00:07:17,060 particle here so you take a given 156 00:07:22,329 --> 00:07:20,629 particle they're completely you move it 157 00:07:25,329 --> 00:07:22,339 for some reason you have a disturbance 158 00:07:27,399 --> 00:07:25,339 that moves it up and here it moves on 159 00:07:30,350 --> 00:07:27,409 the adiabatic profile and then here 160 00:07:32,420 --> 00:07:30,360 because it's denser than its environment 161 00:07:35,600 --> 00:07:32,430 if we'll be pushed back by buoyancy and 162 00:07:38,559 --> 00:07:35,610 you have a stable atmosphere now what 163 00:07:44,029 --> 00:07:38,569 happens if you have the the the reverse 164 00:07:48,339 --> 00:07:44,039 the reversed conditions here now your 165 00:07:53,679 --> 00:07:48,349 gradient in the atmosphere is bigger and 166 00:07:59,029 --> 00:07:53,689 if you have your parcel of air going up 167 00:08:03,140 --> 00:07:59,039 then you're less dense and you you your 168 00:08:05,540 --> 00:08:03,150 particle is a boost up again so little 169 00:08:07,760 --> 00:08:05,550 disturbance is further amplified and 170 00:08:09,649 --> 00:08:07,770 that's what we call convection and that 171 00:08:12,770 --> 00:08:09,659 means that your convection happens 172 00:08:14,450 --> 00:08:12,780 basically when your gradient is bigger 173 00:08:17,119 --> 00:08:14,460 than the adiabatic gradient and that's 174 00:08:21,290 --> 00:08:17,129 what we call the well known for chill 175 00:08:23,180 --> 00:08:21,300 criterion now as I said we want to 176 00:08:25,939 --> 00:08:23,190 include min molecular weight we want to 177 00:08:30,740 --> 00:08:25,949 add another another parameter so we have 178 00:08:33,889 --> 00:08:30,750 to go bit further and then again we have 179 00:08:38,930 --> 00:08:33,899 our thermal gradient but what can happen 180 00:08:42,139 --> 00:08:38,940 is that you can add a gradient update 181 00:08:45,259 --> 00:08:42,149 for calm ego so you have your 182 00:08:47,210 --> 00:08:45,269 particulate that went up now the thing 183 00:08:48,680 --> 00:08:47,220 is in your environment you don't only 184 00:08:52,189 --> 00:08:48,690 have a thermal gradient you also have a 185 00:08:54,949 --> 00:08:52,199 gradient of the heavy element okay so as 186 00:08:58,610 --> 00:08:54,959 you see here you would imagine that your 187 00:09:00,170 --> 00:08:58,620 particle is for example lighter than its 188 00:09:02,569 --> 00:09:00,180 environment but as you see the color is 189 00:09:05,120 --> 00:09:02,579 not the same so here this particle still 190 00:09:08,780 --> 00:09:05,130 has the same composition as here and 191 00:09:12,710 --> 00:09:08,790 basically it is a shown well wet by the 192 00:09:15,139 --> 00:09:12,720 by this term here the gradient of mean 193 00:09:17,720 --> 00:09:15,149 molecular weight in the environment can 194 00:09:19,430 --> 00:09:17,730 offset the effect of temperature and 195 00:09:22,310 --> 00:09:19,440 basically you see that it's a negative 196 00:09:26,269 --> 00:09:22,320 sign so basically if you have more Eva 197 00:09:28,670 --> 00:09:26,279 stuff below it will stabilize you at 198 00:09:31,069 --> 00:09:28,680 magenta so that's what can happen here 199 00:09:36,500 --> 00:09:31,079 where basically your density gradient 200 00:09:39,019 --> 00:09:36,510 will be a little bit lower and here is a 201 00:09:41,860 --> 00:09:39,029 new criterion to know whether this is 202 00:09:43,960 --> 00:09:41,870 going to be stable or not and this is 203 00:09:46,329 --> 00:09:43,970 inverse this is a lot of 204 00:09:49,449 --> 00:09:46,339 Italian and this is basically involving 205 00:09:51,490 --> 00:09:49,459 your thermal gradient you mean molecular 206 00:09:53,790 --> 00:09:51,500 weight gradient in the in the 207 00:09:57,009 --> 00:09:53,800 environment and your adiabatic region 208 00:10:00,519 --> 00:09:57,019 but of course as we saw the problem is 209 00:10:02,290 --> 00:10:00,529 here this is only if you have no 210 00:10:04,569 --> 00:10:02,300 compositional change in your bubble and 211 00:10:06,910 --> 00:10:04,579 because basically you have let's say 212 00:10:09,249 --> 00:10:06,920 dust or something that can be really 213 00:10:13,240 --> 00:10:09,259 affected without changing but what 214 00:10:18,639 --> 00:10:13,250 happens for implementation because here 215 00:10:20,139 --> 00:10:18,649 you see that as you your environment is 216 00:10:22,809 --> 00:10:20,149 going to have a gradient of temperature 217 00:10:24,639 --> 00:10:22,819 and Composition but then in your bubble 218 00:10:26,800 --> 00:10:24,649 as it evolves because there is going to 219 00:10:29,679 --> 00:10:26,810 be condensation so there is going to be 220 00:10:32,230 --> 00:10:29,689 also a change in temperature and in 221 00:10:34,449 --> 00:10:32,240 composition and you have to put terminal 222 00:10:36,790 --> 00:10:34,459 in a mix in there and so I guess you can 223 00:10:42,309 --> 00:10:36,800 now understand that you have to add this 224 00:10:44,679 --> 00:10:42,319 motor and that's where basically you can 225 00:10:47,980 --> 00:10:44,689 feel that it's it's gonna it's gonna get 226 00:10:52,210 --> 00:10:47,990 pretty machine can't you because you see 227 00:10:53,949 --> 00:10:52,220 the big equations coming so if you can't 228 00:10:56,259 --> 00:10:53,959 either because you're very bright 229 00:10:58,269 --> 00:10:56,269 Oh bear smell because actually there is 230 00:11:01,660 --> 00:10:58,279 a very very interesting thing happening 231 00:11:04,720 --> 00:11:01,670 if it's magic of thermodynamics because 232 00:11:07,629 --> 00:11:04,730 basically if you're in a saturated 233 00:11:09,280 --> 00:11:07,639 atmosphere it means that your gradients 234 00:11:11,769 --> 00:11:09,290 of mini molecular weight or your 235 00:11:14,619 --> 00:11:11,779 gradient of water vapor is you will is 236 00:11:16,780 --> 00:11:14,629 going to be linked to the moment just 237 00:11:20,350 --> 00:11:16,790 because of condensation condensation 238 00:11:22,480 --> 00:11:20,360 loss so these two cannot evolve 239 00:11:25,929 --> 00:11:22,490 separately and these two are the same 240 00:11:28,389 --> 00:11:25,939 this one will the condensation so the 241 00:11:30,400 --> 00:11:28,399 amount the saturation will depend on 242 00:11:32,619 --> 00:11:30,410 temperature as well and so basically 243 00:11:34,720 --> 00:11:32,629 what happens is that all this is 244 00:11:36,549 --> 00:11:34,730 proportional to the thermal gradient all 245 00:11:38,590 --> 00:11:36,559 this is proportional to thermal gradient 246 00:11:42,340 --> 00:11:38,600 and the thermal gradients disappear and 247 00:11:46,439 --> 00:11:42,350 you have a magic new criterion where 248 00:11:50,619 --> 00:11:46,449 basically you just know that convection 249 00:11:53,650 --> 00:11:50,629 is shut down whenever your amount of 250 00:11:56,429 --> 00:11:53,660 water vapor in the atmosphere is bigger 251 00:11:57,490 --> 00:11:56,439 than some magic critical abundance and 252 00:12:00,910 --> 00:11:57,500 that 253 00:12:02,800 --> 00:12:00,920 depends only on the difference of the 254 00:12:06,000 --> 00:12:02,810 mid molecular weight between your vapor 255 00:12:09,580 --> 00:12:06,010 or your your commencing species and your 256 00:12:11,800 --> 00:12:09,590 non Comanche species and about the 257 00:12:13,570 --> 00:12:11,810 channel thermo dynamical properties of 258 00:12:16,900 --> 00:12:13,580 your condensation so basically the 259 00:12:18,910 --> 00:12:16,910 latent heat so how does it go what does 260 00:12:23,860 --> 00:12:18,920 it do to your atmosphere so basically 261 00:12:26,350 --> 00:12:23,870 what happens is that you have here your 262 00:12:29,920 --> 00:12:26,360 moisture pause fear dry they're bad if 263 00:12:32,700 --> 00:12:29,930 you have an internal amount of water 264 00:12:35,620 --> 00:12:32,710 vapor that is below this critical value 265 00:12:37,600 --> 00:12:35,630 you'll find but when it's above this 266 00:12:40,150 --> 00:12:37,610 critical value basically what happens 267 00:12:43,360 --> 00:12:40,160 you start here to suppress convection 268 00:12:45,760 --> 00:12:43,370 and then you only have radiation to get 269 00:12:47,710 --> 00:12:45,770 you energy out so you get a relative 270 00:12:50,980 --> 00:12:47,720 layer and so you have a very big 271 00:12:54,880 --> 00:12:50,990 increase in temperature somehow you heat 272 00:12:58,510 --> 00:12:54,890 again the value of your internal amount 273 00:13:01,240 --> 00:12:58,520 of water or all those species and then 274 00:13:03,490 --> 00:13:01,250 you fall back on the dry adiabat the 275 00:13:05,800 --> 00:13:03,500 question is what species are interesting 276 00:13:07,630 --> 00:13:05,810 to do this what I did is just compute 277 00:13:10,210 --> 00:13:07,640 this for different species and you can 278 00:13:12,400 --> 00:13:10,220 do it for for all the others but that 279 00:13:14,320 --> 00:13:12,410 doesn't tell you the whole story we also 280 00:13:17,920 --> 00:13:14,330 have to look for what are the species 281 00:13:21,910 --> 00:13:17,930 that are really abundant in the universe 282 00:13:24,220 --> 00:13:21,920 and so you just put in the for example 283 00:13:25,750 --> 00:13:24,230 the solar abundance and you see here the 284 00:13:29,950 --> 00:13:25,760 enrichment that an atmosphere should 285 00:13:31,950 --> 00:13:29,960 need to have to actually show this kind 286 00:13:34,750 --> 00:13:31,960 of behavior and you see that the most 287 00:13:36,850 --> 00:13:34,760 the most promising is of course is water 288 00:13:40,090 --> 00:13:36,860 you only need a ten times the solar 289 00:13:45,040 --> 00:13:40,100 enrichment and then ch4 and then nh3 and 290 00:13:47,800 --> 00:13:45,050 maybe iron but so so that's that's 291 00:13:50,290 --> 00:13:47,810 really interesting so what does it do if 292 00:13:52,930 --> 00:13:50,300 you look at for example Jupiter here is 293 00:13:54,670 --> 00:13:52,940 a profile so you just add the observed 294 00:13:58,210 --> 00:13:54,680 value at one bar for the temperature and 295 00:14:00,940 --> 00:13:58,220 here is BIOS profile as you increase the 296 00:14:04,329 --> 00:14:00,950 amount of water vapor or the oxygen 297 00:14:05,829 --> 00:14:04,339 amount if you will in in Jupiter and 298 00:14:08,470 --> 00:14:05,839 what you see that the internal temp 299 00:14:10,170 --> 00:14:08,480 attraction decrease with the amount of 300 00:14:13,350 --> 00:14:10,180 water vapor in Jupiter but 301 00:14:15,480 --> 00:14:13,360 if you account for this inhibition from 302 00:14:17,820 --> 00:14:15,490 infection basically that completely 303 00:14:19,620 --> 00:14:17,830 change the the type of profiles you 304 00:14:21,930 --> 00:14:19,630 would have and that changed the internal 305 00:14:25,110 --> 00:14:21,940 temperature so the thing is that I think 306 00:14:27,410 --> 00:14:25,120 it would be it could be maybe detectable 307 00:14:29,970 --> 00:14:27,420 with Juno although there may be some 308 00:14:31,949 --> 00:14:29,980 program of degeneracy is within the 309 00:14:35,070 --> 00:14:31,959 measurement but the planet that it 310 00:14:36,840 --> 00:14:35,080 probably requires too high amount of 311 00:14:40,199 --> 00:14:36,850 water it's actually interesting because 312 00:14:42,810 --> 00:14:40,209 it does explain the properties of Saturn 313 00:14:45,600 --> 00:14:42,820 and so if you want to put that in the 314 00:14:47,670 --> 00:14:45,610 occupied context of course you can think 315 00:14:50,880 --> 00:14:47,680 of when every node for example in 316 00:14:53,280 --> 00:14:50,890 hydrogen acid but now I want to quickly 317 00:14:55,500 --> 00:14:53,290 move to another area which is well why 318 00:14:57,389 --> 00:14:55,510 does that matter to brown dwarfs so of 319 00:14:59,639 --> 00:14:57,399 course Brown rods or maybe not that 320 00:15:03,139 --> 00:14:59,649 metal which but where does compositional 321 00:15:05,970 --> 00:15:03,149 conviction could play so there is this 322 00:15:08,220 --> 00:15:05,980 long-standing problem that when you go 323 00:15:10,590 --> 00:15:08,230 to the see the brown drop sequence in 324 00:15:12,810 --> 00:15:10,600 the color of magnitude diagram you have 325 00:15:16,140 --> 00:15:12,820 this wiggle here that we call the MLC 326 00:15:17,910 --> 00:15:16,150 transition and the price that you need 327 00:15:21,930 --> 00:15:17,920 to have something to actually explain 328 00:15:24,720 --> 00:15:21,940 this and to explain this basically you 329 00:15:26,190 --> 00:15:24,730 need to read on all these L words and to 330 00:15:28,050 --> 00:15:26,200 read on a brand watch you need to 331 00:15:33,870 --> 00:15:28,060 decrease the brightness temperature the 332 00:15:35,010 --> 00:15:33,880 brightness difference between you are to 333 00:15:36,980 --> 00:15:35,020 decrease the brightness temperature in 334 00:15:40,430 --> 00:15:36,990 the near-infrared is that you have 335 00:15:44,550 --> 00:15:40,440 mostly one way which is to put something 336 00:15:47,250 --> 00:15:44,560 higher like clouds the address issue 337 00:15:49,500 --> 00:15:47,260 well that will emit higher from colder 338 00:15:51,360 --> 00:15:49,510 regions and then you can expand that or 339 00:15:53,790 --> 00:15:51,370 the problem is that there is some 340 00:15:55,829 --> 00:15:53,800 characterization going on so there's 341 00:15:59,340 --> 00:15:55,839 been another ideas in the literature 342 00:16:00,750 --> 00:15:59,350 which is to basically cool down the deep 343 00:16:03,569 --> 00:16:00,760 atmosphere and that does the thing 344 00:16:05,670 --> 00:16:03,579 without sharks but of course I just want 345 00:16:09,660 --> 00:16:05,680 to remind you that even though this 346 00:16:11,280 --> 00:16:09,670 could work I don't exactly see how you 347 00:16:13,470 --> 00:16:11,290 could have ground was without that 348 00:16:15,690 --> 00:16:13,480 because you are financing things so they 349 00:16:19,610 --> 00:16:15,700 need to connect at some point but anyway 350 00:16:22,140 --> 00:16:19,620 let's try to work it with with this and 351 00:16:22,770 --> 00:16:22,150 so there was this really interesting by 352 00:16:24,630 --> 00:16:22,780 I 353 00:16:27,120 --> 00:16:24,640 your Pascal from running is going to 354 00:16:29,280 --> 00:16:27,130 talk just after which is the fact that 355 00:16:31,890 --> 00:16:29,290 this transition actually occurs at a 356 00:16:33,960 --> 00:16:31,900 chemical transition between Co dominated 357 00:16:35,640 --> 00:16:33,970 and huge for dominated atmosphere and 358 00:16:37,500 --> 00:16:35,650 that's interesting because if you look 359 00:16:38,700 --> 00:16:37,510 at this huge food immunity that with you 360 00:16:41,850 --> 00:16:38,710 you basically have an atmosphere like 361 00:16:44,790 --> 00:16:41,860 this this is a little bit colder you 362 00:16:46,920 --> 00:16:44,800 have ch4 which gas all the way and so 363 00:16:49,290 --> 00:16:46,930 you mean molecular weight doesn't do 364 00:16:52,470 --> 00:16:49,300 anything and it's stable if you go to a 365 00:16:55,110 --> 00:16:52,480 little bit hotter things then you have 366 00:16:57,630 --> 00:16:55,120 Co gas down there and teach for which 367 00:17:01,170 --> 00:16:57,640 gas up there the thing is that the siege 368 00:17:04,230 --> 00:17:01,180 for which gas is actually a bit heavier 369 00:17:06,540 --> 00:17:04,240 than the still gas and so basically this 370 00:17:08,670 --> 00:17:06,550 is potentially unstable and so that 371 00:17:10,290 --> 00:17:08,680 would lead to mixing and that's what I 372 00:17:15,150 --> 00:17:10,300 really loved about this idea because 373 00:17:17,670 --> 00:17:15,160 it's really you think this and say well 374 00:17:20,120 --> 00:17:17,680 instability should really offer what I 375 00:17:23,579 --> 00:17:20,130 didn't so much like about this idea that 376 00:17:27,929 --> 00:17:23,589 the way they implemented this mixing was 377 00:17:30,540 --> 00:17:27,939 mostly making it acts like diffusion and 378 00:17:33,330 --> 00:17:30,550 that makes sense so basically what they 379 00:17:36,000 --> 00:17:33,340 did is saying okay we have a turbulent 380 00:17:37,890 --> 00:17:36,010 flux lag that we write like this so if 381 00:17:40,920 --> 00:17:37,900 we have some mixing process we increase 382 00:17:43,140 --> 00:17:40,930 the disk AGG so to have the same flux 383 00:17:45,600 --> 00:17:43,150 will just decrease the thermal gradient 384 00:17:49,830 --> 00:17:45,610 and basically you go from a stable 385 00:17:52,800 --> 00:17:49,840 atmosphere that is like this to more of 386 00:17:54,450 --> 00:17:52,810 a family atmosphere and it kind of makes 387 00:17:56,250 --> 00:17:54,460 sense as well because intuitively you 388 00:17:58,380 --> 00:17:56,260 would think okay we have we have mixing 389 00:17:59,790 --> 00:17:58,390 so basically what does mixing do as we 390 00:18:02,100 --> 00:17:59,800 heard for for the earth 391 00:18:04,980 --> 00:18:02,110 you take energy there and you put it 392 00:18:07,170 --> 00:18:04,990 down so you kind of always put energy 393 00:18:09,600 --> 00:18:07,180 report so you you would put two two more 394 00:18:11,850 --> 00:18:09,610 I for summer conditions the problem is 395 00:18:15,360 --> 00:18:11,860 that it's actually what happens when you 396 00:18:17,520 --> 00:18:15,370 have a convective the unstable regions 397 00:18:19,920 --> 00:18:17,530 but here you're forcing mixing in a 398 00:18:22,670 --> 00:18:19,930 convective least stable region and so 399 00:18:25,970 --> 00:18:22,680 actually what does happen is that mixing 400 00:18:29,100 --> 00:18:25,980 mixes enthalpy it doesn't mix 401 00:18:30,360 --> 00:18:29,110 temperature so basically it's not the 402 00:18:32,870 --> 00:18:30,370 turbulent flux is not written like that 403 00:18:36,010 --> 00:18:32,880 it's written like that as a flux of 404 00:18:39,280 --> 00:18:36,020 turbulence of entropy and 405 00:18:41,290 --> 00:18:39,290 basically when you remember when you up 406 00:18:44,320 --> 00:18:41,300 meant when you increase the turbulence 407 00:18:46,270 --> 00:18:44,330 by any process what you do is not going 408 00:18:49,540 --> 00:18:46,280 to more and more isothermal you go to 409 00:18:52,660 --> 00:18:49,550 other more adiabatic conditions and and 410 00:18:55,500 --> 00:18:52,670 even though it's continuity that you can 411 00:18:57,940 --> 00:18:55,510 show from the Ida dynamical literature 412 00:19:00,490 --> 00:18:57,950 theorems that show that actually in a 413 00:19:04,000 --> 00:19:00,500 stable a to say to mix you actually go 414 00:19:07,630 --> 00:19:04,010 toward at about you actually bury it so 415 00:19:11,049 --> 00:19:07,640 you have a negative flux of heat and 416 00:19:13,900 --> 00:19:11,059 basically instead of of going to more 417 00:19:17,169 --> 00:19:13,910 algebra isothermal conditions you have 418 00:19:19,180 --> 00:19:17,179 more adiabatic conditions and so instead 419 00:19:21,490 --> 00:19:19,190 of decreasing the temperature of the 420 00:19:23,980 --> 00:19:21,500 Lord Michelle this actually increase the 421 00:19:27,669 --> 00:19:23,990 temperature the higher the lower 422 00:19:29,470 --> 00:19:27,679 atmosphere so like that I don't think 423 00:19:35,650 --> 00:19:29,480 this process can really really work 424 00:19:38,110 --> 00:19:35,660 however I know that Pascal after a lot 425 00:19:42,390 --> 00:19:38,120 of dishes well it worked a lot and he 426 00:19:46,090 --> 00:19:42,400 actually found the place I think to 427 00:19:48,400 --> 00:19:46,100 actually make it work if you convection 428 00:19:50,860 --> 00:19:48,410 now is not added at the batting as I 429 00:19:52,210 --> 00:19:50,870 said but if there is some source of 430 00:19:55,360 --> 00:19:52,220 energy and in this case I think 431 00:19:58,299 --> 00:19:55,370 radiation pouring this tradition I think 432 00:20:00,400 --> 00:19:58,309 that I or at least I hope this is a good 433 00:20:15,340 --> 00:20:00,410 transition to the next door and with 434 00:20:20,060 --> 00:20:18,230 hi Hugo and at University of Exeter 435 00:20:23,150 --> 00:20:20,070 have you thought about the effect of 436 00:20:24,860 --> 00:20:23,160 convective entrainment when you move to 437 00:20:26,480 --> 00:20:24,870 jump on plan atmospheres in other words 438 00:20:28,820 --> 00:20:26,490 where you have so you have these plumes 439 00:20:32,210 --> 00:20:28,830 of rising fluid and on earth what 440 00:20:33,980 --> 00:20:32,220 happens if those enter a dry region and 441 00:20:36,140 --> 00:20:33,990 it pulls in dry air that tends to 442 00:20:38,210 --> 00:20:36,150 downtown the convection but if you're 443 00:20:44,290 --> 00:20:38,220 putting in a lighter fluid like hydrogen 444 00:20:50,360 --> 00:20:47,630 tell you where we're trying in it's 445 00:20:52,430 --> 00:20:50,370 trying to to actually resolving Falls of 446 00:20:54,290 --> 00:20:52,440 this kind of thing because it's really 447 00:20:55,880 --> 00:20:54,300 where you can see this kind of effect 448 00:21:03,500 --> 00:20:55,890 because you cannot resolve the 449 00:21:09,230 --> 00:21:05,560 [Music] 450 00:21:11,600 --> 00:21:09,240 the in terms of the inhibition high 451 00:21:12,470 --> 00:21:11,610 abundances first their water with 452 00:21:14,450 --> 00:21:12,480 Jupiter or whatever 453 00:21:16,160 --> 00:21:14,460 it seems like the criterion you 454 00:21:17,950 --> 00:21:16,170 described is basically a local criteria 455 00:21:20,510 --> 00:21:17,960 and the looks just very sort of you know 456 00:21:22,430 --> 00:21:20,520 you know instantaneous or not 457 00:21:24,230 --> 00:21:22,440 instantaneous Bavarian infinitesimal 458 00:21:25,640 --> 00:21:24,240 kind of perturbations given some local 459 00:21:27,290 --> 00:21:25,650 gradient and it seems like you can 460 00:21:29,360 --> 00:21:27,300 potentially get around that criterion if 461 00:21:32,090 --> 00:21:29,370 the convection is non-local like if you 462 00:21:34,130 --> 00:21:32,100 have external perturbations large-scale 463 00:21:37,130 --> 00:21:34,140 waves or whatever that push the parcel 464 00:21:40,310 --> 00:21:37,140 up by finite amount then basically 465 00:21:43,340 --> 00:21:40,320 condenses and then you can bring out the 466 00:21:44,810 --> 00:21:43,350 the condensate and so in that case you 467 00:21:46,430 --> 00:21:44,820 have removed the thing that inhibited 468 00:21:47,750 --> 00:21:46,440 the convection maybe the molecular mass 469 00:21:50,030 --> 00:21:47,760 drops back down to something approaching 470 00:21:51,560 --> 00:21:50,040 to and yet you're still retained the the 471 00:21:53,900 --> 00:21:51,570 latent heating effect which is the point 472 00:21:56,210 --> 00:21:53,910 factor so it seems like that could sort 473 00:22:00,470 --> 00:21:56,220 of circumvent the whole you know 474 00:22:04,070 --> 00:22:00,480 criterion what could what gives me some 475 00:22:06,110 --> 00:22:04,080 confidence I said that maybe you find 476 00:22:08,630 --> 00:22:06,120 the finite effect that you describe 477 00:22:12,590 --> 00:22:08,640 maybe needs to be too big is that 478 00:22:16,220 --> 00:22:12,600 actually so it seems to be observing 479 00:22:19,070 --> 00:22:16,230 some 2d in some to the 480 00:22:25,070 --> 00:22:19,080 Modelling so basically where you add the 481 00:22:28,400 --> 00:22:25,080 finite effects and and the other thing 482 00:22:31,070 --> 00:22:28,410 is so of course it's it's a long shot 483 00:22:33,260 --> 00:22:31,080 but there is some evidence that actually 484 00:22:36,200 --> 00:22:33,270 the the the great white film from Saturn 485 00:22:38,720 --> 00:22:36,210 the the spacing between them the time 486 00:22:42,049 --> 00:22:38,730 between them is actually consistent with 487 00:22:43,730 --> 00:22:42,059 exactly the prediction of this model 488 00:22:46,039 --> 00:22:43,740 because basically where you have this 489 00:22:50,570 --> 00:22:46,049 mobile gather the relative barrier it 490 00:22:52,789 --> 00:22:50,580 has some depth in pattern and the the 491 00:22:55,970 --> 00:22:52,799 relative timescale of the atmosphere 492 00:22:59,060 --> 00:22:55,980 above this buyer that is the decouple 493 00:23:01,909 --> 00:22:59,070 from the bottom is exactly the timescale 494 00:23:04,220 --> 00:23:01,919 between the two between two big 495 00:23:07,070 --> 00:23:04,230 eruptions and so basically that what we 496 00:23:10,120 --> 00:23:07,080 showed by Leon Ingersoll that you can 497 00:23:12,440 --> 00:23:10,130 actually have your big storm event 498 00:23:14,360 --> 00:23:12,450 heating up the atmosphere and you need 499 00:23:16,760 --> 00:23:14,370 exactly to cool down just the this 500 00:23:19,340 --> 00:23:16,770 atmosphere above this relative layer and 501 00:23:21,049 --> 00:23:19,350 then up you start up again and so you 502 00:23:26,890 --> 00:23:21,059 build on this in a gene that's why we 503 00:23:29,600 --> 00:23:26,900 have such great storms and pattern but 504 00:23:32,350 --> 00:23:29,610 yeah so there you mentioned the question 505 00:23:35,750 --> 00:23:32,360 about mixing entropy versus mixing 506 00:23:38,419 --> 00:23:35,760 temperature but the problem entropy is 507 00:23:40,850 --> 00:23:38,429 not conserved under mixing so so it's 508 00:23:44,000 --> 00:23:40,860 true that you want to shut off the 509 00:23:45,530 --> 00:23:44,010 mixing when you're on the 80 of that but 510 00:23:48,530 --> 00:23:45,540 but actually the thing that's conserved 511 00:23:50,060 --> 00:23:48,540 during convection is enthalpy yeah in 512 00:23:51,200 --> 00:23:50,070 mixing enthalpy but you don't want to 513 00:23:52,220 --> 00:23:51,210 mix enthalpy either because that's 514 00:23:53,930 --> 00:23:52,230 that's like missing temperature so 515 00:23:56,120 --> 00:23:53,940 actually the right thing to do I think 516 00:24:00,020 --> 00:23:56,130 it's to mix enthalpy but they have the 517 00:24:02,390 --> 00:24:00,030 kaze ed said go to zero as as the 518 00:24:04,490 --> 00:24:02,400 gradient entropy goes to zero so it's 519 00:24:08,450 --> 00:24:04,500 not I think neither neither of this 520 00:24:12,799 --> 00:24:08,460 mixing is quite right but no no some I 521 00:24:16,070 --> 00:24:12,809 mean well you make in the end if you 522 00:24:17,840 --> 00:24:16,080 have mixing you enthalpy is constant 523 00:24:19,430 --> 00:24:17,850 even though it's not concert in the 524 00:24:22,070 --> 00:24:19,440 beginning to the end but that's a train 525 00:24:24,020 --> 00:24:22,080 but it go to defuse it defusing entropy 526 00:24:25,820 --> 00:24:24,030 leads to the case where your entropy 527 00:24:28,039 --> 00:24:25,830 your integrated entry is the same at the 528 00:24:29,810 --> 00:24:28,049 beginning in the end so that that's why 529 00:24:31,670 --> 00:24:29,820 if you just do KZ Ed's Edwin 530 00:24:35,720 --> 00:24:31,680 it'll give you the rider that's not what 531 00:24:37,520 --> 00:24:35,730 I did tell ya I mean Here I am NOT 532 00:24:40,730 --> 00:24:37,530 putting any numerical models it's 533 00:24:43,010 --> 00:24:40,740 actually only an icicle things what I'm 534 00:24:47,420 --> 00:24:43,020 just showing and I mean you can look at 535 00:24:49,520 --> 00:24:47,430 the paper there is a just a proven 536 00:24:52,190 --> 00:24:49,530 theorem you take the equations and you 537 00:24:54,560 --> 00:24:52,200 can show that in an atmosphere where 538 00:24:58,460 --> 00:24:54,570 when you are in the stable region if you 539 00:25:00,710 --> 00:24:58,470 do mix you will actually have tracked 540 00:25:05,870 --> 00:25:00,720 down one so you will heat up the lower