Director's Notices and Some
in 2005

1.   #01 (24 July GMT, Façade News C)

2.   #02 (04 August GMT, email to David MOORE)

3.   #03 (16 October GMT, email to Christophe PELLIER)

4.   #04 (18 October GMT, CMO Notice #1)

5.   #05 (22 October GMT, CMO Notice #2)

6.   #06 (07 November GMT, Façade News F)

7.   #07 (01 December GMT, CMO Notice #3)


Noachis at λ=250°Ls

  The areocentric longitude of the Sun λ=250°Ls is memorial since the great Noachis dust storm in 1956 was onset just at this season. This year 250°Ls visited on 16 July and Noachis began to face toward us from around 19 July (λ=252°Ls). So at the Fukui City Observatory, NAKAJIMA and MINAMI have been on the alert from around 2 o'clock AM local time (17:00 GMT) every night to catch a lull (still rainy season here). As far as they watched visually the surface extensively around from ω=330°W~340°W on 19 July, 20 July, 21 July and 24 July (this morning), no dust disturbance has been detected over Noachis (unfortunately on 22 and 23 July the planet did not appear here, while we have just received good images made on 22 July from Yukio MORITA). M Serpentis has remained the same, wide and darkened. Furthermore no dust disturbance has been there around the western neighbourhood of Hellas: Hellas is just dull light and rather misty whitish near the terminator and has remained the same on 19, 20, 21 and 24 July (λ=256°Ls). As rotated, Argyre appeared distinct near the noon. Noachis is still visible for another few days from here, while a Typhoon (970hPa, No 7) is approaching us and we are afraid we cannot observe the area any longer until we pass on the baton to the European observers.

(Mn: 24 July at 22 hrs GMT)

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From: "Masatsugu MINAMI"

To: David MOORE

Cc: <>

Date: Fri, 5 Aug 2005 04:34:20 +0900

Subject: RE:Mars - August 04, 2005


Dear Dave,


It is our great pleasure to begin to receive your observations after a while. We hope you will be more successful this apparition.


We congratulate you on your clear detection of the roll cloud over Arsia Mons on 4 August (λ=263°Ls) at ω: ω=120°W and 127°W. As far as we know, it was observed recently by Damian Peach on 22 July (λ=254°Ls) and by Don Parker on 29 July (λ=259°Ls). The cloud on Peach's B image on the Gallery is obscure but he has another clear one. Anyway it must have been subtle yet. As Don says in his case also it must have been hard to see it visually through Wr47.


Since Arsia Mons is located at Ω=120°W, and at present the phase angle (we denote it by ι) is 47° 


the summit on your cases at ω=120°W and at ω=127°W as situated about respectively 47° and (47-7)° before the terminator. In other words it was about 47/15=2:45 to 40/15=3:10 hours before the sundown. So quite orographics.


The trend of the rise and fall of the Arsia cloud is quite different from the Olympus cloud (which will never be seen this apparition before opposition) and especially the strength of the Arsia cloud is variable (or tend to fluctuate) even when it is believed to be active (the Olympus case is more distinct, always active when it is in the active period). So every observation of Arsia Mons is valuable. Thus your image on 4 Aug is very precious.


As another case at 275°Ls in 1988, we cited a Japanese observation in


(where Olympus Mons was lit - because of the opposition effect - since the phase angle was quite small: ι=8°.)


For your information, I shall cite some passages from my email sent recently to Damian Peach.


>There are known several differences between the Olympus cloud and Arsia

>cloud: 1) The Olympus cloud ceases to be active before λ=200°Ls, while

>the Arsia cloud looks to survive all seasons as Don exactly noted. 2) The

>peak of the Olympus cloud activity is around λ=100 - 120°Ls, while the

>peak of the Arsia cloud comes after λ=150°Ls. 3) Furthermore, the Olympus

>cloud rather constantly active when it is active, but in the case of the

>Arsia cloud the activity is quite fluctuated if we look at the data obtained

>by the MGS-MOC; that implies sometimes the cloud happens to be inactive even

>when the season is supposed to be the most active period around λ=150°Ls.

>So the activity of the Arsia Mons should be told "statistically", and so we

>need many more data.


>The difference of period of the Arsia cloud from the Olympus cloud

>(concerning 2)) is reasoned: because the water vapour immigration from the

>northern to the southern hemisphere occurs from λ=150°Ls to 230°Ls (while

>the water vapour supply to Olympus Mons from the north polar cap ceases from

>around the period the npc attains minimal). As to the fluctuation (3)) of the

>activity, as I suppose it may be because of the complex topography around

>Arsia Mons, and in reality the shape of the Arsia cloud appears deformed in

>different time in a complex manner.


>The statistics of the cloud activity of Tharsis Montes and others from 15

>March 1999 to 31 July 2001 was given by J L Benton and others in Icarus 165

>(2003) 34-52 (*) in which activity of the Arsia cloud in 1999 is shown to

>statistically decrease from around λ=180°Ls and the graph suggests the

>minimum to occur around λ=250°Ls. However in the 1999 case, the Arsia

>cloud became inactive at around λ=230°Ls. Benton and others reasoned

>its inactivity (at λ=227 -235°Ls) was because of the cross-equatorial dust storm

>pinned down by B A Cantor and others (**) at λ=226-227°Ls. (Here a total of 783

>dust storms are listed from λ=107°Ls to 274°Ls). It might have been

>so, but as far as I look, its decreasing curve looks different from the

>sudden inactivity occurred when the 2001 global dust storm reached there. In

>1999 the decreasing is gradual much before the advent of the dust at λ=226°Ls

>and it can be supposed its minimum comes along sooner or later at around λ=250°Ls

>(or before). In the case of 1999, there seems to have arisen a rather

>sudden wider cloud at λ=245°Ls and then became inactive again and finally

>restarted at around λ=260°Ls to rise. The second peak came at around λ=290 – 325°Ls.


>As to the 2003 case before opposition I have an intension to scrutinise the

>rise and fall of the Arsia cloud from the CMO gallery images someday, though

>I am sure the result cannot be complete. As far as I just looked, there seems

>to exist a few images (by Pellier and Valimberti and others) which show a

>minimal cloud at Arsia at around λ=230 -237°Ls near the terminator in 2003.



As you know, the 2003 Mars was at opposition at around λ=250°Ls, and so it became difficult to watch the evening Arsia Mons after λ=250°Ls. So we should say this apparition must provide a very good chance to trace the Arsia cloud until the end of October. I shall emphasize this point again in the next CMO issue citing your images as well as Peach's and Don's, though we cautioned already in CMO #307 that it could revive soon again.


Thank you very much for your calling attention to the Arsia cloud on your images, and we look forward to your further work,


With best wishes,




>  (*) The seasonal behaviour of water ice clouds in the Tharsis and Valles Marineris regions of Mars: Mars Orbiter Camera Observations, Icarus 165 (2003) 34-52.

>(**) Martian dust storm: 1999 Mars Orbiter Camera Observations, JGR 106 (2001) 23653-23687.


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From “Masatsugu MINAMI”

To:Christophe PELLIER

Cc: M Murakami, T Asada

Date: Sun, 16 Oct 2005 16:12:39 +0900

Subject: RE:Mars on october 15th


Dear Christophe,


I was very pleased to hear from you about your first detection of a dust disturbance at Eos. Especially I like it because it was found in the morning (my theory is that any dust at the first stage should be onset in the morning or at dawn, and rebuilt next morning).


I am here at Mt Hamilton near San Jose (from 3 Oct), and so it is gratifying for me to catch the area much earlier than the case I might have stayed in Japan. Yes yesterday (15 Oct nearly at 5.5h GMT before Grafton) I was able to watch the area near the terminator, but unfortunately the seeing was terrible because the low pressure air was approaching. Just I judged the area was duller than Ophir which looked well bright and so not so developed. Tonight, unfortunately again, the weather remained poor and it is foggy and windy, and so no observation (really any operator does not appear; without them the monster refractor of Lick does not move) is possible. I hope the east coast has been endowed with a fine sky and we may hear soon much of good news. I expect so "tomorrow":


This kind of dust disturbance makes a quantum jump on the following day, sometime appearing weaker or making a burst in a different place. Anyway I hope this event will continue for more than a fortnight. We are here watching the area of Solis L at present, and though I shall return home on 25 October, but then the area of Solis L must again be facing to Japan, and so if the event should repeat longer I shall be able to watch it quite longer.


Good luck for you (already), and good sky for me (tomorrow).


With best wishes,




PS: The deserts of the planet Mars appears really "ruddy" to me through the 20cm refractor. I am so also concerned with the colour shown up by the Lick refractor here. And we should add there is a culture difference between you and me. We Japanese don't understand why the tawny orange is regarded as "orange"


Another thing: what I said about Jeff Beish's statement was this: I did never think any dust was aloft in Hellas when Hellas was bright near the limb (just when the phase angle was large).


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: Tue, 18 Oct 2005 22:43:12 +0900

From: "Masami MURAKAMI" <>

To: "MINAMI, Masatsugu" <>

Subject: Dust storm at the southern Chryse


(This was sent to the CMO members via BCc)


Dear Mars Colleagues,


Masami and I (CMO) received an email from Silvia KOWOLLIK, Germany, at 1:55 GMT on 18 October (today) informing lively that the area of Chryse was unusual and looked roundish bright at ω=355°W, and subsequently she sent us a raw image taken at just before 3h GMT. Meanwhile Joel WARREN dispatched an image taken at 3:23 GMT. So the area of Chryse came to the American continents.


Since I am staying here at the west coast (at Mt Hamilton), the planet was to be caught after 5h GMT, while the sky condition was poor this evening, and so I did not expected. However, though the seeing condition was terribly poor (furthermore clouds passing), it was apparent, from the outset of the session at 5:30 GMT (ω=048°), that the southern Chryse was dusty bright, really looking roundish. I don't detail my observations here, but this is a real dust storm: I observed then at ω=057°, 067°, 077°, 087° and 096°W until 8:50 GMT. The seeing gradually recovered but the area went to the terminator side.


After staying inside the big dome for 3 hours, I came down to check the internet to find the images made by Don PARKER who already took a good set of images at 4:41 GMT (ω=034°W) and by Dr Clay at 5:01 (ω=041°W) to 7:02 (ω=070°W). We also received a final version of the precious image by KOWOLLIK at 2:44 GMT (ω=008°W), which was already uploaded in our CMO Gallery.


We should add that today's dust storm if seen through naked eyes looked much bigger and brighter, looked as if bounded by a shadowy roundish band, apparently brighter than the following Ophir. Around from ω=087°W, the eastern border became fainted and finally the dust looked mingled with the evening white mist. The Lick refractor was used with its OG stopped down to 50cm with a magnification of 500×. Bill SHHEHAN was not here: I was helped by Rem STONE and Tony MISCH.


At present, GRAFTON's image at 6:42 GMT (ω=065°W) and GASKELL’s one at 4:41 GMT (ω=036°W) have been reported. (Should be added PHILLIPS’s at 07:00 (ω=070°W).)


I think this is a rare case in that the onset dust was chased from an early moment (KOWOLLIK) and to the evening. This dust was of course was related with the precursor found by Ch PELLIER on 13/14 October. The off-again on-again series of the dust disturbances are not rare: For instance in the case of December 2003 dust storm, it repeated first an on-but-off-again jumps even before 12 December as shown by TES.


Anyway it was gone, and may be subsided at night, but tomorrow it will make a quantum jump.


With best wishes,


Masatsugu MINAMI (CMO/OAA) at Mt Hamilton


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Date: Sat, 22 Oct 2005 23:13:03 +0900

From: "Masami MURAKAMI" <>

To: "MINAMI, Masatsugu" <>

Subject: Dust Strom at Solis L (CMO Notice #2)


(Sent to the CMO members based on our mailing list by BCc)


Dear Colleagues,


There is a possibility that a great dust storm may be onset from the Solis L area.


Last night (21 October GMT), as we first observed (here at Mt Hamilton), the Chryse area, which was brilliant with the dust on 18 October, looked recovered since it showed a usual reddish colour and the similar bright dust patch was no more than a roundish one found at an area following Argyre. Just it was quite natural the dust trend moved southward. The south circumpolar region however was wine-coloured and so looked dust free yet. However as the area of Solis L came into the inside, we saw the situation was not so simple since a brilliant core was observed on the eastern part of Solis L, the place having a considerable slope: This reminded us of the situation in 1973 and really in October 1973 nearly in the similar Martian season, a small core of bright dust on Solis L developed gradually to a great dust storm. So the next morning change of the dust core was interesting.


Tonight (22 October GMT), the area came into sight around from 6h GMT, and the clear dust core area was looked larger and showed a shape similar to the one we saw in 1973 in a developing stage. The dust area on Solis L (almost covered except for the western outline) has still a brilliant core at the lower part and so still energetic. The covering sands of lower Thaumasia must have been blown up since M Erythræum looked as if moved to westward. The eastern end of weaker dust covering was seen up to 350°W in Noachis tonight. Observations were made by the use of the 36" Lick refractor (stopped down to 50cm) with magnification 500×, tutored by Tony MISCH. Seeing was moderate.


The trend of the present Solis L dust storm will be fixed within a few days: The area of Solis L begins now to come into view from the hemisphere of Oceania-Asia, and if the case is similar to the one in 1973, the following (westward) regions of Solis L are as well important, and so we hope the observers are on the alert.


With best wishes


Masatsugu MINAMI at Mt Hamilton on 22 October at 10h GMT



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Yellow Planet again at Opposition

  Mars was closest to the Earth on 30 October, and today came at opposition. Tomorrow De and Ds will coincide. Surface shines and especially the aureole of Olympus Mons should be bright as usual because of nearly vanishing phase angle (an opposition effect) and so on. However due to the preceding dust events, the Martian atmosphere is full of airborne dusts and the general dark markings appear to be rather dull (except for the IR eyes). We are now observing the regions from Syrtis Mj to Solis L from Japan, while the general aspect is quite different from what we saw one month ago. The surface disk looks quite yellowish; though just the northern deserts of Æria to Moab show yet a ruddy tint (of course more yellowish, yellow ochre).
  A small dust disturbance at Eos observed on 13/14 Oct (λ=306°Ls) was latent for a while but made a one-day bright burst on 18 Oct (λ=308°Ls) at the southern Chryse, and then jumped to the southern hemisphere. The dust resonance onset on 21 Oct (λ=310°Ls) at Solis L was strong and stayed there for four days and continued to make dusts aloft. On 25 Oct, a lower half of Solis L became visually visible, but this implied a lot of dusts had been already brought into the high altitudes, and the dust effect could be serious (since the disappearance does never imply any fallout at present). At those times, Noachis was already quite dusty and the southern Margaritifer S was faded. On 27 Oct Margaritifer S disappeared, and on 28 Oct (λ=314°Ls) there occurred a considerable dust disturbance near
Aram. (In 1973, there were also observed two bright dust bursts near Aram to Deucalionis R and at Eos to M Erythræum on the sixth day after the onset on Solis L. So this year the propagation of the resonance was very slow and weak.) On 30 Oct (λ=315°Ls), a spectacular scene of deformed Meridiani S was recorded in the US. Margaritifer S looks now recovering, but the southern markings are never normal affected by the dust expansion. It is desirable for any imager to watch visually the surface and not to enhance the R ingredient too much.

(Mn; on 7 November)

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: Thu, 1 Dec 2005 09:38:54 +0900

From: "Masami MURAKAMI" <>

To: "MINAMI, Masatsugu" <>

Cc: "Masami MURAKAMI" <>

Subject: CMO Notice #3/2005


(Emailed to the CMO members via BCc by the use of the CMO emailing list)


Dear CMO Mars Colleagues


This is a note on recent Mars from Japan: Olympus Mons began to face to us in Japan, first after opposition, around from 20 November (λ=327°Ls, phase angle ι= 11°), and on 26 - 27 November (phase angles ι=16 – 18°) it came into sight on the CM. Because of the dismal weather we have not been able to check every angle, but we could catch the angles Olympus Mons should have been near the limb on 21 and 22 November (phase angle ι= 13°): In any case it was dull and did not appear as a bright spot area. We suppose the results in Melbourne are quite the same.


The aureole of Olympus Mons which was shown up as an opposition effect was first checked explicitly in Europe on 29 October (λ=315°Ls, phase angle ι= 8°) by AMADORI at ω =188°W, and then on 31 October (phase angle = 6 degrees) by HIDALGO at ω=187, 194°W. As the phase angle decreased, its brightness increased. PEACH's images on 3 November (phase angle = 4 degrees) at ω =170 degrees and on 6 November (phase angle =2 degrees) at ω=138°W belong to the most beautiful pictures ever taken of the brightening Olympus-Mons aureole as well as the summit.


On 6 November, it was first shot in the US by WALKER at ω=189°W and then lots of observers followed. Notable was that at those times the European observers caught it as a still bright spot on the morning side. After opposition, however, as the phase angle gradually increased, the brightening of aureole decreased. As a result, as stated above, perhaps no Japanese observers were able to see the brightening Olympus Mons this time since the phase angle was over 10° when it began to face toward us.


Note that Olympus Mons is located 28°N, while the slope of the flank has an angle of 20 to 30°, and so the area looks as if located more southward near the angle (DS +DE) /2. At opposition the surface is as if in a full-moon state, and the high albedo areas increased their brightness by some dozens per cent and so this difference of angles enhances the particular areas (originally the "opposition effect" was used to denote the brightening of the high albedo areas seen through the shorter wave lengths. Nowadays, the presence of the blue haze is regarded as dubious.) In 2003, (DS +DE)/2 was more southward about by 6°, and hence it was possible that the Olympus-Mons aureole was less bright in 2003 than this year if the airborne dust condition was the same at opposition.


There was few possibility that such a large diurnal brightening was caused by the so-called orographic cloud (as to another few possibility see below). The fact that any B ccd image showed a large roundish spot (that is, there was witnessed no irregularity of the shape common to the roll clouds) must have just implied that it was mostly sensitive to the white light. In this sense B 390 combined with TP2415 must have been more discriminating. See an example in 1988 (its (DS +DE) /2 at opposition was similar to that in 2003):


The activity of discrete white cloud at Olympus Mons was once reported by S A SMITH and B A SMITH: Diurnal and Seasonal Behavior of Discrete White Clouds on Mars, Icarus 16 (1972) 509, based on the data from 1963 to 1971 of the New Mexico State University Observatory supplemented by the data of the Lowell Observatory Planetary Data Center (going back to 1924) and IAU Data Center at the Meudon Observatory. According to their results, the cloud begins very faintly from around λ=325°Ls, and stays very weak from λ=000°Ls to about 050°Ls, and becomes very active around from λ=060°Ls. More recent result based on the MGS images was published by J L BENTON and others: The seasonal behavior of water ice clouds in the Tharsis and Valles Marineris regions of Mars: Mars Orbiter Camera Observations, Icarus 165 (2003) 34. According to their results, Olympus-Mons Cloud starts to rise from λ=350°Ls and increases steadily in size from λ=050°Ls to 085°Ls and shows a peak at around λ=120°Ls (data from June 200 to July 2001). However they seemed to identify a smaller scale white matter than the Olympus-Mons aureole during a short period around λ=325°Ls (perhaps from the data at around March and April 2000, having an area of less than a few hundred km squared). So this kind of white matter (maybe frozen) must have possibly been mingled with the opposition effect this year also, but apparently the scale is very different from the usual orographic cloud (having usually an area of 5~800000 km squared). Note MGS's data are limited to the swath at the 2 o'clock PM while SMITH-SMITH's are supposed to be diurnal.


The high-altitude atmospheric dust scattered aloft by the several dust resonances observed from the end of October to the beginning of November looks to have much subsided though still the dark markings appear to be duller. However the airborne dust might have been used as water cloud condensation nuclei, and so the watching of the water condensates on the southern hemisphere will be next interesting:


On the other hand, we should still be cautious about the dust disturbances which may occur on the northern high latitude areas eventually to cross the equator since the period B denoted in


is still available (period B: λ=310 – 350°Ls). Incidentally just after the temporal onset of a dust streak in Chryse found by WARREN and GRAFTON on 23 November (λ=329°Ls), the area around of Eos Chasma appeared quite dusty light: See for example WALKER's images on 26 November


The area is going to face toward us, and we hope the observers in the Oceania-Asian hemisphere to check the aftermath. Unfortunately however in Japan they say a cold wave will visit us this week end to the next week, and so we are not certain we will be able to obtain reliable results. How about in Melbourne?


With best wishes,


Masatsugu MINAMI



PS: We are sorry we are quite late in editing up CMO #312 and #313 as well as #287.


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