1 00:00:10,610 --> 00:00:08,629 so I realize I'm the only thing standing 2 00:00:13,310 --> 00:00:10,620 between you and your free time and your 3 00:00:15,499 --> 00:00:13,320 dinner so I will endeavor to be as 4 00:00:17,930 --> 00:00:15,509 interesting as possible and hopefully 5 00:00:20,660 --> 00:00:17,940 give you a bit of information to take 6 00:00:22,849 --> 00:00:20,670 with you my name is Victoria hartwick 7 00:00:25,040 --> 00:00:22,859 I'm also one of the contingent of people 8 00:00:29,839 --> 00:00:25,050 who work just down the road at 9 00:00:32,749 --> 00:00:29,849 cu-boulder but I put up a very 10 00:00:34,240 --> 00:00:32,759 complicate or complicated title but I'm 11 00:00:36,770 --> 00:00:34,250 since this is an interdisciplinary 12 00:00:38,840 --> 00:00:36,780 conference I'm going to try to take a 13 00:00:41,360 --> 00:00:38,850 bit of a step back and show how this 14 00:00:43,880 --> 00:00:41,370 work can be relevant to other planetary 15 00:00:46,400 --> 00:00:43,890 systems but also within an astra 16 00:00:50,420 --> 00:00:46,410 biological context so with that in mind 17 00:00:51,979 --> 00:00:50,430 I've tried to create two points as a 18 00:00:55,459 --> 00:00:51,989 sort of framework for the rest of this 19 00:00:58,549 --> 00:00:55,469 talk the first of which is no man and no 20 00:01:01,130 --> 00:00:58,559 planet is an island and we may need to 21 00:01:04,369 --> 00:01:01,140 really consider planetary climate in a 22 00:01:06,440 --> 00:01:04,379 within the context of a broader system 23 00:01:07,910 --> 00:01:06,450 so when we typically think of planetary 24 00:01:10,550 --> 00:01:07,920 climate we think of factors that are 25 00:01:13,250 --> 00:01:10,560 endogenous to that planet we think about 26 00:01:18,289 --> 00:01:13,260 the composition of the atmosphere any 27 00:01:23,330 --> 00:01:18,299 type of any type of volcanic activity 28 00:01:25,100 --> 00:01:23,340 the fraction of water to land but it may 29 00:01:27,469 --> 00:01:25,110 be equally important to consider factors 30 00:01:30,350 --> 00:01:27,479 that are external to the system so 31 00:01:34,069 --> 00:01:30,360 things like the evolution of the solar 32 00:01:36,890 --> 00:01:34,079 output the impact on the short and long 33 00:01:39,590 --> 00:01:36,900 term of asteroidal impacts and in the 34 00:01:42,700 --> 00:01:39,600 case of this research what is the effect 35 00:01:46,120 --> 00:01:42,710 of a continuous flux of small particles 36 00:01:49,160 --> 00:01:46,130 at the top of the Mars atmosphere and 37 00:01:51,530 --> 00:01:49,170 secondly it's not always necessary to 38 00:01:54,530 --> 00:01:51,540 reinvent the scientific wheel so to 39 00:01:56,359 --> 00:01:54,540 speak and we can easily apply lessons 40 00:02:00,080 --> 00:01:56,369 from Earth climate research to other 41 00:02:01,670 --> 00:02:00,090 planets so with that I'll say that my 42 00:02:03,709 --> 00:02:01,680 research is primarily concerned with the 43 00:02:06,109 --> 00:02:03,719 micro physics of clouds which is just a 44 00:02:08,660 --> 00:02:06,119 fancy way of saying how do we determine 45 00:02:11,320 --> 00:02:08,670 where clouds form in the atmosphere and 46 00:02:13,720 --> 00:02:11,330 at what rate they form 47 00:02:16,630 --> 00:02:13,730 and if there is one thing I could have 48 00:02:18,370 --> 00:02:16,640 you take away from this it's that in 49 00:02:20,980 --> 00:02:18,380 almost all environmental conditions 50 00:02:23,370 --> 00:02:20,990 clouds form heterogeneous Lee which 51 00:02:25,240 --> 00:02:23,380 means water vapor or some other gaseous 52 00:02:27,880 --> 00:02:25,250 component of the atmosphere is 53 00:02:29,980 --> 00:02:27,890 condensing onto a particle that's also 54 00:02:32,110 --> 00:02:29,990 suspended in the same environment and 55 00:02:34,000 --> 00:02:32,120 that's what I'm trying to show here is 56 00:02:36,490 --> 00:02:34,010 we have a particle also called a cloud 57 00:02:40,510 --> 00:02:36,500 condensation nuclei or ice nuclei on 58 00:02:42,610 --> 00:02:40,520 which ambient high water gas can 59 00:02:45,340 --> 00:02:42,620 condense to form a cloud droplet and 60 00:02:50,380 --> 00:02:45,350 then grow to form a larger cloud droplet 61 00:02:52,630 --> 00:02:50,390 on Mars the only known source of ice or 62 00:02:56,740 --> 00:02:52,640 cloud condensation nuclei is surface 63 00:02:58,890 --> 00:02:56,750 mineral dust for those of you who aren't 64 00:03:02,320 --> 00:02:58,900 familiar i'll do a quick cartoon 65 00:03:06,160 --> 00:03:02,330 depiction of the cloud and water cycles 66 00:03:08,290 --> 00:03:06,170 on Mars so you have wind blowing across 67 00:03:10,060 --> 00:03:08,300 the surface if it's sufficiently strong 68 00:03:12,699 --> 00:03:10,070 it induces a process called saltation 69 00:03:15,400 --> 00:03:12,709 which is lost dust particles into the 70 00:03:17,830 --> 00:03:15,410 air at the same time you an exchange of 71 00:03:20,790 --> 00:03:17,840 water vapor seasonally from the polar 72 00:03:25,090 --> 00:03:20,800 caps and on a diurnal time scale from 73 00:03:26,890 --> 00:03:25,100 ground ice and absorbed water now if you 74 00:03:28,180 --> 00:03:26,900 have suspended dust particles in regions 75 00:03:31,180 --> 00:03:28,190 of the atmosphere which are super 76 00:03:33,940 --> 00:03:31,190 saturated with respect to water you get 77 00:03:36,310 --> 00:03:33,950 clouds now this seems pretty neat and 78 00:03:38,740 --> 00:03:36,320 tidy and you may be wondering what I'm 79 00:03:41,560 --> 00:03:38,750 going to talk about for the next six to 80 00:03:43,750 --> 00:03:41,570 seven minutes and it's there's a big 81 00:03:46,780 --> 00:03:43,760 problem and I made the slide red because 82 00:03:49,360 --> 00:03:46,790 it's a big problem and that's when we 83 00:03:51,100 --> 00:03:49,370 look at the model simulations of cloud 84 00:03:53,530 --> 00:03:51,110 formation how closely do they actually 85 00:03:57,280 --> 00:03:53,540 match the observations that we have and 86 00:03:59,259 --> 00:03:57,290 the answer is not very well especially 87 00:04:01,479 --> 00:03:59,269 when we consider the vertical 88 00:04:04,270 --> 00:04:01,489 distribution of water ice clouds in the 89 00:04:08,350 --> 00:04:04,280 atmosphere and these are three examples 90 00:04:11,170 --> 00:04:08,360 of extinction versus altitude plots from 91 00:04:15,340 --> 00:04:11,180 the spycam instrument so what you see on 92 00:04:17,920 --> 00:04:15,350 the bottom is extinct extinction of due 93 00:04:20,740 --> 00:04:17,930 to water ice particles per kilometer 94 00:04:22,640 --> 00:04:20,750 versus altitude from 10 to 70 kilometers 95 00:04:26,120 --> 00:04:22,650 above the surface 96 00:04:29,140 --> 00:04:26,130 and I've put an orangish yellowish line 97 00:04:31,719 --> 00:04:29,150 at 1 e to the negative 4 because that's 98 00:04:34,700 --> 00:04:31,729 significant amounts of extinction and 99 00:04:37,310 --> 00:04:34,710 this top plot is kind of what our models 100 00:04:38,689 --> 00:04:37,320 can reproduce where we have a high 101 00:04:40,790 --> 00:04:38,699 amount of extinctions near the surface 102 00:04:43,670 --> 00:04:40,800 that falls off by about 20 to 30 103 00:04:45,710 --> 00:04:43,680 kilometers but often in these 104 00:04:48,050 --> 00:04:45,720 observations we have higher altitude 105 00:04:51,200 --> 00:04:48,060 cloud layers that are completely absent 106 00:04:52,879 --> 00:04:51,210 from our GCM model simulations and this 107 00:04:54,080 --> 00:04:52,889 can get really bad especially when you 108 00:04:56,330 --> 00:04:54,090 look at this one where you have clouds 109 00:04:59,990 --> 00:04:56,340 up to 70 kilometers above the surface 110 00:05:02,210 --> 00:05:00,000 and the reason for this discrepancy 111 00:05:04,850 --> 00:05:02,220 between model simulations and 112 00:05:06,439 --> 00:05:04,860 observation is actually the main point 113 00:05:10,010 --> 00:05:06,449 about cloud nucleation that I brought up 114 00:05:12,260 --> 00:05:10,020 before which is if you do not have an 115 00:05:14,659 --> 00:05:12,270 ice nuclei population on which to 116 00:05:17,689 --> 00:05:14,669 condense water you won't get any clouds 117 00:05:19,100 --> 00:05:17,699 at all and the current understanding of 118 00:05:21,260 --> 00:05:19,110 the Mars climate says that the only 119 00:05:24,020 --> 00:05:21,270 source of ice nuclei is surface dust 120 00:05:27,230 --> 00:05:24,030 it's really difficult to loft surface 121 00:05:31,730 --> 00:05:27,240 dust multiple scale heights to above 30 122 00:05:33,589 --> 00:05:31,740 kilometers so what do we do we can 123 00:05:36,500 --> 00:05:33,599 actually look to earth as an analog and 124 00:05:38,149 --> 00:05:36,510 look at high altitude clouds and see how 125 00:05:41,779 --> 00:05:38,159 they nucleate on earth and what they 126 00:05:43,730 --> 00:05:41,789 nuclei on so an example here this nice 127 00:05:45,529 --> 00:05:43,740 picture is naturally some clouds which 128 00:05:47,839 --> 00:05:45,539 are serious water ice clouds that form 129 00:05:49,820 --> 00:05:47,849 at the north polar winter which is 130 00:05:52,310 --> 00:05:49,830 really cold region of the earth 131 00:05:55,159 --> 00:05:52,320 atmosphere that's similar to Mars 132 00:05:57,850 --> 00:05:55,169 conditions and what these clubs are 133 00:06:00,379 --> 00:05:57,860 nucleate on nucleating on is actually 134 00:06:01,939 --> 00:06:00,389 micrometeorite ablation by products 135 00:06:04,990 --> 00:06:01,949 which just means the smoke particles 136 00:06:07,219 --> 00:06:05,000 that form when small micrometer 137 00:06:11,420 --> 00:06:07,229 particles impacting the upper atmosphere 138 00:06:13,969 --> 00:06:11,430 burn up and these are some examples I 139 00:06:15,529 --> 00:06:13,979 can find my pointer of micrometer 140 00:06:17,420 --> 00:06:15,539 particles that we've actually captured 141 00:06:19,969 --> 00:06:17,430 in the Earth's atmosphere but there's a 142 00:06:24,290 --> 00:06:19,979 remote signature of this process which 143 00:06:26,719 --> 00:06:24,300 is elevated ionized metals high in the 144 00:06:30,680 --> 00:06:26,729 atmosphere so you see this elevation and 145 00:06:32,750 --> 00:06:30,690 sodium magnesium iron and this signature 146 00:06:34,700 --> 00:06:32,760 has been seen on Mars as well so we have 147 00:06:38,450 --> 00:06:34,710 direct evidence that this micrometer 148 00:06:40,490 --> 00:06:38,460 ablation process is happening on Mars so 149 00:06:42,050 --> 00:06:40,500 the question becomes could these micro 150 00:06:44,120 --> 00:06:42,060 meteorites be responsible for the high 151 00:06:46,490 --> 00:06:44,130 altitude clouds that we see on Mars and 152 00:06:49,570 --> 00:06:46,500 even a broader question tweening takes 153 00:06:52,010 --> 00:06:49,580 consider some process external to a 154 00:06:54,200 --> 00:06:52,020 planetary system to explain a 155 00:06:58,100 --> 00:06:54,210 fundamental aspect of that planet's 156 00:07:00,320 --> 00:06:58,110 climate so to answer this question I've 157 00:07:02,089 --> 00:07:00,330 used the Morris cam karma general 158 00:07:04,790 --> 00:07:02,099 circulation model and this was developed 159 00:07:08,420 --> 00:07:04,800 in partnership between n car and last 160 00:07:11,810 --> 00:07:08,430 and this is kind of just a depiction of 161 00:07:13,129 --> 00:07:11,820 what a GCM is and how it works if you'd 162 00:07:14,420 --> 00:07:13,139 like more information I'm not going to 163 00:07:17,089 --> 00:07:14,430 go into it here but you can always find 164 00:07:20,300 --> 00:07:17,099 me but what we did and this is a nice 165 00:07:22,100 --> 00:07:20,310 artist's rendition we just added 7,500 166 00:07:23,719 --> 00:07:22,110 tons of microbe you direct material 167 00:07:27,649 --> 00:07:23,729 which sounds like a lot but as a 168 00:07:31,940 --> 00:07:27,659 fraction of what is what we get on earth 169 00:07:34,969 --> 00:07:31,950 every year so 7,500 tons per year and we 170 00:07:38,019 --> 00:07:34,979 just distributed it evenly in time and 171 00:07:41,180 --> 00:07:38,029 in space across the top of the model and 172 00:07:43,159 --> 00:07:41,190 i'll show you some quick results so here 173 00:07:44,420 --> 00:07:43,169 again it's a similar I've apologized for 174 00:07:46,879 --> 00:07:44,430 all the lines I'll try to walk through 175 00:07:50,330 --> 00:07:46,889 it again we have extinction on the 176 00:07:52,310 --> 00:07:50,340 bottom and the 10 to the my or one to 177 00:07:54,140 --> 00:07:52,320 the minus four is marked by that line 178 00:07:57,890 --> 00:07:54,150 again and again altitude on the y axis 179 00:08:00,620 --> 00:07:57,900 from 0 to 70 and these are just zonally 180 00:08:02,269 --> 00:08:00,630 averaged latitude bands but what you'll 181 00:08:04,610 --> 00:08:02,279 see is when we have new micro meteorites 182 00:08:06,320 --> 00:08:04,620 we do get some elevated layers but 183 00:08:10,490 --> 00:08:06,330 they're all the extinction is really low 184 00:08:13,100 --> 00:08:10,500 and most of the high extinctions fall 185 00:08:15,170 --> 00:08:13,110 off below 20 or 30 kilometers but the 186 00:08:18,200 --> 00:08:15,180 second we add this micro meteoritic 187 00:08:21,500 --> 00:08:18,210 source you get elevated extinctions 188 00:08:24,290 --> 00:08:21,510 about 30 but also these enhancements at 189 00:08:26,329 --> 00:08:24,300 high altitude around 50 and above and 190 00:08:28,939 --> 00:08:26,339 again this is a zonal average so we're 191 00:08:31,390 --> 00:08:28,949 kind of smashing out some of these 192 00:08:33,769 --> 00:08:31,400 really high altitude interesting layers 193 00:08:35,659 --> 00:08:33,779 but the takeaway point is when we add 194 00:08:39,740 --> 00:08:35,669 micrometeorites we really enhance cloud 195 00:08:42,239 --> 00:08:39,750 extinctions at all latitudes and at all 196 00:08:50,079 --> 00:08:47,019 secondly this is there is an observed 197 00:08:53,800 --> 00:08:50,089 seasonal cycle in the hay stop the haze 198 00:08:55,600 --> 00:08:53,810 top is just basically the highest 199 00:08:58,410 --> 00:08:55,610 altitude in your atmosphere where you 200 00:09:01,150 --> 00:08:58,420 have significant extinction from clouds 201 00:09:03,489 --> 00:09:01,160 there's a basic seasonal pattern that we 202 00:09:07,379 --> 00:09:03,499 see that corresponds with the orbit of 203 00:09:10,869 --> 00:09:07,389 Mars we're early in the year which is 204 00:09:12,939 --> 00:09:10,879 here when we're in northern summer or 205 00:09:15,970 --> 00:09:12,949 southern or northern winter southern 206 00:09:17,679 --> 00:09:15,980 summer the haze top is low and then when 207 00:09:20,369 --> 00:09:17,689 we warm up in the intense southern 208 00:09:23,619 --> 00:09:20,379 summer the haze top Rises but the 209 00:09:25,900 --> 00:09:23,629 addition of micrometeorites generally 210 00:09:28,929 --> 00:09:25,910 raises the haze top globally and you 211 00:09:32,980 --> 00:09:28,939 also get this interesting enhancement in 212 00:09:35,110 --> 00:09:32,990 the haze top / polar winter and this 213 00:09:36,730 --> 00:09:35,120 corresponds with some observations and 214 00:09:39,249 --> 00:09:36,740 there's not a really good there's no 215 00:09:42,340 --> 00:09:39,259 global coverage of the haze top so I 216 00:09:45,400 --> 00:09:42,350 don't have a good data comparison but 217 00:09:51,160 --> 00:09:45,410 you can maybe believe me when I say this 218 00:09:52,629 --> 00:09:51,170 is comparable so finally what's 219 00:09:54,759 --> 00:09:52,639 interesting to note is when we change 220 00:09:56,740 --> 00:09:54,769 the distribution of ice nuclei it's not 221 00:10:00,670 --> 00:09:56,750 just where the clouds are it also 222 00:10:03,119 --> 00:10:00,680 influences how we r where the clouds are 223 00:10:05,710 --> 00:10:03,129 in across the latitudes and longitudes 224 00:10:08,049 --> 00:10:05,720 also how high they are in the atmosphere 225 00:10:12,249 --> 00:10:08,059 and the radiative impact of these clouds 226 00:10:14,290 --> 00:10:12,259 which can be really large so to speak 227 00:10:16,840 --> 00:10:14,300 very generally if you have fewer ice 228 00:10:19,509 --> 00:10:16,850 nuclei you get larger cloud particles as 229 00:10:21,879 --> 00:10:19,519 you increase the number of ice nuclei 230 00:10:23,530 --> 00:10:21,889 you get smaller cloud particles and this 231 00:10:25,360 --> 00:10:23,540 changes the way that it interacts with 232 00:10:29,290 --> 00:10:25,370 radiation so when you have large 233 00:10:30,999 --> 00:10:29,300 particles more of the light gets down to 234 00:10:33,129 --> 00:10:31,009 the surface and less is reflected to 235 00:10:35,619 --> 00:10:33,139 space so that can have obviously a big 236 00:10:37,809 --> 00:10:35,629 impact on your climate also the side of 237 00:10:40,150 --> 00:10:37,819 these particles changes a lifetime that 238 00:10:42,489 --> 00:10:40,160 cloud stay in the atmosphere and whether 239 00:10:45,460 --> 00:10:42,499 you snow immediately upon falling or can 240 00:10:47,679 --> 00:10:45,470 move water and precipitation to lower 241 00:10:49,689 --> 00:10:47,689 latitudes so if you look at the amount 242 00:10:52,210 --> 00:10:49,699 of water in the atmosphere versus time 243 00:10:55,330 --> 00:10:52,220 when you add these micro meteorites you 244 00:10:59,310 --> 00:10:55,340 can get water to reach to 245 00:11:03,550 --> 00:11:01,660 so just briefly closed by talking about 246 00:11:06,160 --> 00:11:03,560 the Mars paleoclimate and how this 247 00:11:08,380 --> 00:11:06,170 research applies to it and this is kind 248 00:11:10,360 --> 00:11:08,390 of the big question in paleo climate 249 00:11:13,240 --> 00:11:10,370 right now which is what martyrs warm and 250 00:11:15,070 --> 00:11:13,250 wet or cold and icy so this is just a 251 00:11:19,600 --> 00:11:15,080 depiction of those two competing 252 00:11:22,420 --> 00:11:19,610 hypotheses of early Mars and what we 253 00:11:24,460 --> 00:11:22,430 found in very preliminary research is 254 00:11:27,850 --> 00:11:24,470 that having high altitude clouds that 255 00:11:29,920 --> 00:11:27,860 are large with large particle sizes you 256 00:11:33,100 --> 00:11:29,930 can sustain a warm Martian climate 257 00:11:37,750 --> 00:11:33,110 without artificially enhancing the 258 00:11:39,550 --> 00:11:37,760 atmosphere by adding different just 259 00:11:42,010 --> 00:11:39,560 different chemical components that we 260 00:11:44,890 --> 00:11:42,020 don't see real evidence of being there 261 00:11:46,960 --> 00:11:44,900 so with this new model we can look at 262 00:11:49,480 --> 00:11:46,970 how the vertical distribution of this 263 00:11:52,000 --> 00:11:49,490 these water out water ice clouds 264 00:11:54,100 --> 00:11:52,010 influence the radiative environment and 265 00:11:56,680 --> 00:11:54,110 also look at how the particle size and 266 00:11:57,940 --> 00:11:56,690 distribution will impact that so 267 00:12:01,120 --> 00:11:57,950 hopefully that can get a little more 268 00:12:03,940 --> 00:12:01,130 information so just to close I'll try to 269 00:12:05,770 --> 00:12:03,950 summarize remember clouds form 270 00:12:07,750 --> 00:12:05,780 heterogeneous ly so you need an ice 271 00:12:10,450 --> 00:12:07,760 nuclei population to form clouds or else 272 00:12:12,580 --> 00:12:10,460 you just get a supersaturated atmosphere 273 00:12:14,980 --> 00:12:12,590 so the problem with the current 274 00:12:17,560 --> 00:12:14,990 generation of Mars general circulation 275 00:12:19,540 --> 00:12:17,570 models that we can't loft ice nuclei to 276 00:12:22,000 --> 00:12:19,550 high enough altitudes to reproduce the 277 00:12:24,280 --> 00:12:22,010 clouds that we actually observe but on 278 00:12:26,530 --> 00:12:24,290 earth high altitude clouds nucleate on 279 00:12:28,180 --> 00:12:26,540 micro meteorites so we tried to look at 280 00:12:31,090 --> 00:12:28,190 that and see if we could reproduce these 281 00:12:32,410 --> 00:12:31,100 high clouds and as it looks now we can 282 00:12:35,350 --> 00:12:32,420 so this is really promising an 283 00:12:37,270 --> 00:12:35,360 interesting quirk so if you have any 284 00:12:39,310 --> 00:12:37,280 questions this is since you're all 285 00:12:42,250 --> 00:12:39,320 talking about Iceland this is me at one 286 00:12:44,950 --> 00:12:42,260 of the Mars analog sites and so you can 287 00:12:46,240 --> 00:12:44,960 remember who i am and find you later but 288 00:12:51,769 --> 00:12:46,250 you can also follow me on twitter or 289 00:13:05,519 --> 00:13:02,220 question lots of questions um so you 290 00:13:08,430 --> 00:13:05,529 mentioned that the the tonnage of 291 00:13:10,320 --> 00:13:08,440 micrometeorites was fairly low how did 292 00:13:13,230 --> 00:13:10,330 you come up with the number for that as 293 00:13:16,920 --> 00:13:13,240 this is just an extrapolation basically 294 00:13:18,210 --> 00:13:16,930 by what we from Earth to the Mars orbit 295 00:13:22,500 --> 00:13:18,220 based on what we know of the 296 00:13:24,360 --> 00:13:22,510 distribution of microbial in the current 297 00:13:26,579 --> 00:13:24,370 solar system but obviously this is going 298 00:13:28,139 --> 00:13:26,589 to change with time so if we rewind the 299 00:13:30,230 --> 00:13:28,149 clock to paleoclimate it should be 300 00:13:33,360 --> 00:13:30,240 different and there's actually a lot of 301 00:13:35,930 --> 00:13:33,370 complexity with the distribution of 302 00:13:38,130 --> 00:13:35,940 meteorite material with season 303 00:13:40,050 --> 00:13:38,140 potentially so there's a lot of work to 304 00:13:42,240 --> 00:13:40,060 do here but we've done different 305 00:13:43,620 --> 00:13:42,250 simulations that test kind of 306 00:13:46,680 --> 00:13:43,630 parameterize and go through a space of 307 00:13:51,150 --> 00:13:46,690 this and do 02 / like one hundred fifty 308 00:13:53,220 --> 00:13:51,160 percent of that number I have two 309 00:13:56,970 --> 00:13:53,230 questions so on the slide where you had 310 00:14:01,620 --> 00:13:56,980 the images of the different micro dust 311 00:14:03,660 --> 00:14:01,630 particles micrometers yes um so yeah so 312 00:14:06,120 --> 00:14:03,670 the scale bar you say 50 microns is that 313 00:14:07,860 --> 00:14:06,130 one parcours at multiple at clump 314 00:14:10,710 --> 00:14:07,870 together that's the conglomerate these 315 00:14:12,630 --> 00:14:10,720 are really small and usually that might 316 00:14:15,680 --> 00:14:12,640 be actually a particle that was captured 317 00:14:19,050 --> 00:14:15,690 high in the atmosphere prior to ablation 318 00:14:20,449 --> 00:14:19,060 it in the Earth's atmosphere most of 319 00:14:22,920 --> 00:14:20,459 these are going to ablate completely 320 00:14:26,940 --> 00:14:22,930 unless they're pretty large and then 321 00:14:30,829 --> 00:14:26,950 coagulate to really like point 01 micron 322 00:14:33,269 --> 00:14:30,839 size particles are smaller yeah okay um 323 00:14:34,800 --> 00:14:33,279 another question so in your models do 324 00:14:36,510 --> 00:14:34,810 you ever take into account the different 325 00:14:38,850 --> 00:14:36,520 mechanisms of heterogeneous ice 326 00:14:41,160 --> 00:14:38,860 nucleation because when like 327 00:14:42,780 --> 00:14:41,170 depositional isolation happen like 328 00:14:45,420 --> 00:14:42,790 higher in the atmosphere versus like 329 00:14:47,490 --> 00:14:45,430 what's nice about Mars is the entire and 330 00:14:51,870 --> 00:14:47,500 the entire atmosphere is really really 331 00:14:54,240 --> 00:14:51,880 cold so basically the same nucleation 332 00:14:55,500 --> 00:14:54,250 process that you'd see high in the 333 00:14:57,660 --> 00:14:55,510 Earth's atmosphere is basically 334 00:14:59,460 --> 00:14:57,670 everywhere which is so if anyone is 335 00:15:05,970 --> 00:14:59,470 earned earth scientists here if Mars can 336 00:15:12,699 --> 00:15:09,519 um so when you're looking at the like 337 00:15:15,040 --> 00:15:12,709 paleo climate of Mars do you I take into 338 00:15:18,340 --> 00:15:15,050 consideration that that the Sun should 339 00:15:21,879 --> 00:15:18,350 be fainter early sources yeah I mean 340 00:15:24,129 --> 00:15:21,889 that's basically why these this icy 341 00:15:26,650 --> 00:15:24,139 highlands hypothesis originated because 342 00:15:29,040 --> 00:15:26,660 with I mean you can't even really get 343 00:15:31,150 --> 00:15:29,050 Mars that warm now and if you reduce the 344 00:15:34,210 --> 00:15:31,160 luminosity of the sun by that much it's 345 00:15:40,780 --> 00:15:34,220 really difficult to warm the surface 346 00:15:43,000 --> 00:15:40,790 consistently I was wondering how long 347 00:15:46,210 --> 00:15:43,010 you expect these clouds to stay 348 00:15:49,480 --> 00:15:46,220 suspended it really depends on where 349 00:15:52,180 --> 00:15:49,490 they are the polar clouds for example 350 00:15:53,829 --> 00:15:52,190 it's pretty super saturated in that 351 00:15:56,800 --> 00:15:53,839 region so they can grow really quickly 352 00:15:59,610 --> 00:15:56,810 and then we get snowfall very quickly in 353 00:16:02,819 --> 00:15:59,620 that region but if you change the 354 00:16:06,490 --> 00:16:02,829 parameters ations of the nucleation 355 00:16:10,439 --> 00:16:06,500 process they can be smaller and stay 356 00:16:12,430 --> 00:16:10,449 suspended so we see clouds that 357 00:16:14,889 --> 00:16:12,440 originated near the poles and they're 358 00:16:17,860 --> 00:16:14,899 able to kind of drift down into the 359 00:16:20,439 --> 00:16:17,870 equatorial regions okay and then one 360 00:16:21,880 --> 00:16:20,449 other comment was I know in exoplanets 361 00:16:23,980 --> 00:16:21,890 there's high altitude Hayes's that 362 00:16:26,980 --> 00:16:23,990 they're blocking give any insight into 363 00:16:30,730 --> 00:16:26,990 this mechanism as a possible explanation 364 00:16:34,269 --> 00:16:30,740 for that no but I can wildly speculate 365 00:16:36,910 --> 00:16:34,279 oh it should be to say that there's no 366 00:16:40,530 --> 00:16:36,920 reason why this micrometeoroid material 367 00:16:43,360 --> 00:16:40,540 would be only in our solar system so I 368 00:16:47,350 --> 00:16:43,370 think it'd be potentially important 369 00:16:49,420 --> 00:16:47,360 factor to consider and I think just as a 370 00:16:51,100 --> 00:16:49,430 point that we need to we can't just look 371 00:16:54,340 --> 00:16:51,110 at these planets in isolation and there 372 00:16:56,199 --> 00:16:54,350 may be other stuff going on well i'm at 373 00:16:58,720 --> 00:16:56,209 mistis do we know the green size 374 00:17:08,559 --> 00:16:58,730 distribution of dust partly goes on Mars 375 00:17:11,500 --> 00:17:08,569 doesn't matter um yes and no we know a 376 00:17:13,780 --> 00:17:11,510 fair amount about low atmosphere grain 377 00:17:15,769 --> 00:17:13,790 sizes we know that there's a population 378 00:17:17,779 --> 00:17:15,779 an extremely small part of 379 00:17:20,329 --> 00:17:17,789 kohl's at high altitudes but it's 380 00:17:23,359 --> 00:17:20,339 difficult to tell if this is dust or ice 381 00:17:25,399 --> 00:17:23,369 so it's kind of hard to decon volute 382 00:17:27,549 --> 00:17:25,409 that and also these grain size 383 00:17:29,629 --> 00:17:27,559 retrievals are based on usually two 384 00:17:36,409 --> 00:17:29,639 wavelengths that most and a lot of 385 00:17:38,690 --> 00:17:36,419 assumptions like how much let me come in 386 00:17:40,129 --> 00:17:38,700 you guys got into the air in the first 387 00:17:42,409 --> 00:17:40,139 yeah I definitely I mean if you have a 388 00:17:44,570 --> 00:17:42,419 much larger particle than expected it's 389 00:17:47,299 --> 00:17:44,580 going to blate with the less at lower 390 00:17:50,570 --> 00:17:47,309 altitudes or less efficiently which 391 00:17:53,320 --> 00:17:50,580 would change the distribution but this 392 00:17:55,789 --> 00:17:53,330 kind of exploratory at this point and 393 00:17:57,200 --> 00:17:55,799 there's a lot of other parameters ations 394 00:17:59,149 --> 00:17:57,210 that we'd probably have to do first but 395 00:18:02,539 --> 00:17:59,159 that's kind of touched in when we change 396 00:18:06,589 --> 00:18:02,549 the amount of meteor material one more 397 00:18:09,799 --> 00:18:06,599 quick question so I'm just so how do you 398 00:18:12,799 --> 00:18:09,809 determine how to distribute the the 399 00:18:15,769 --> 00:18:12,809 micro meteorites spatially in your model 400 00:18:17,989 --> 00:18:15,779 um well right now we just kind of follow 401 00:18:20,930 --> 00:18:17,999 Earth's example and it's pretty uniform 402 00:18:23,619 --> 00:18:20,940 across latitudes and longitudes on earth 403 00:18:27,369 --> 00:18:23,629 and there's some suggestion that there's 404 00:18:29,509 --> 00:18:27,379 distributions in time that vary and 405 00:18:31,999 --> 00:18:29,519 there's definitely a distribution 406 00:18:34,070 --> 00:18:32,009 vertically where you see an enhancement 407 00:18:35,959 --> 00:18:34,080 right at the layer of peak or the 408 00:18:38,419 --> 00:18:35,969 altitude of peak ablation but that's 409 00:18:40,629 --> 00:18:38,429 actually above our model top so we've 410 00:18:44,209 --> 00:18:40,639 kind of skirted around that and just 411 00:18:45,709 --> 00:18:44,219 place it all right at the top but that's