21

st Report:

The CMO/OAA Observations made during a fortnight period

from

16 December 2003 (317Ls)

to

31 December 2003 (326Ls)

 


An OAA Mars Section article to be published in CMO #286 (10 January 2004 issue)


Masatsugu MINAMI, Director of the OAA Mars Section


Japanese version here


T

he apparent diameter decreased already under 10 arcsecs, and the observable time was limited only to the evening. Observations however were active since there had occurred an interesting catastrophe of yellow cloud near Chryse on 12 Dec 2003 (λ=314Ls) (detected on 13 Dec by Don PARKER (DPk)). We here review how the dust disturbance was progressive or degressive during the fortnight period from 16 Dec 2003 (λ=317Ls) to 31 Dec 2003 (λ=326Ls). The apparent diameter δ went down from 9.6" to 8.5", and the phase angle ι was 42. The central latitude φ was 26S, and so the southern hemisphere was well observed. The apparent declination came back to the celestial equator and so the planet shined higher. In Japan, however, the weather condition was poorer especially at the rear side (including Fukui) since the winter-type distribution of atmospheric pressure prevailed. The present writer (Mn), expecting a lull, stayed at the observatory to catch the dust cloud on 17 Dec, but in vain. The opposite side facing to the Pacific Ocean enjoyed fine skies, and KUMAMORI (Km) were able to be quite active. In the US, PARKER (DPk) and GRAFTON (EGf) produced successively fruitful results.

 

T

he observers contributed this time were as follows (a total of 27 observers):

 

AKUTSU, Tomio (Ak) Karasuyama, Tochigi, Japan

7 Sets of CCD Images (+2 IR images)(23, 28, 30 December 2003)

f/3332cm spec with a Bitran BJ-41L

BEISH, Jeffrey D (JBs) Lake Placid, FL, USA

1 Drawing (16 December 2003) 59041cm F/6.9 speculum

BIVER, Nicolas (NBv) Versailles, France

2 Colour Drawings (18 December 2003)

51026cm speculum

BUNGE, Robert (RBg) Bowie, MD, USA

1 Drawing (24 December 2003) 21010cm spec

FRASSATI, Mario (MFr) Crescentino (VC), Italia

1 Drawing (23 December 2003) 40020cm SCT

GRAFTON, Edward A (EGf) Houston, TX, USA

4 CCD Images (18, ~20, 21 December 2003)

f/3935cm SCT with an ST-5C

IWASAKI, Tohru (Iw) KitaKyushu, Fukuoka, Japan

      9 Drawings (16, 21, 23, 28 December 2003)

40021cm speculum

KARRER, Michael (MKr) St Radegund, sterreich

1 CCD Image (20 December 2003)

f/3518cm Meade Refraktor with a ToUcam

KOVACEVIC, Zkatko F (ZKv) Virovitica, Croatia

1 CCD Image (18 December 2003)

f/2020cm STC with a ToUcam

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan 

27 CCD Images (16, 17#, 21#, 23#, 25#, ~27# , 28, 30 December 2003)

f/8420cm Dall-Kirkham & f/4060cm Cass# with a ToUcam

# Sakai City Observatory

LAU, Canon (CLa) Hong-Kong

4 CCD Images (25, 29, 31 December 2003)

f/3235cm SCT with a ToUcam

MELILLO, Frank J (FMl) Holtsville, NY, USA

  2 Red CCD Images (28, 30 December 2003)

20cm SCT with a Starlight Xpress MX5

MINAMI, Masatsugu (Mn) Fukui, Fukui, Japan

12 Drawings (22, 25, 28, 30 December 2003)

480, 40020cm F/12 ED Goto refractor*

* Fukui City Observatory, Fukui

MIYAZAKI, Isao (My) Gushikawa, Okinawa, Japan

6 CCD Images (22, ~24, 29, 30 December 2003)

40cm F/6 speculum with ToUcam

MORITA, Yukio (Mo) Hatsuka-ichi, Hiroshima, Japan

16 Sets of CCD Images (21, 23, 30 December 2003)

25cm spec equipped with an ST-5C

MURAKAMI, Masami (Mk) Yokohama, Kanagawa, Japan

      19 Drawings (16, 17, 21, 22, 23, 24, December 2003)

32020cm speculum

NAKAJIMA, Takashi (Nj) Fukui, Fukui, Japan

9 Drawings (28, 30 December 2003)

480, 40020cm F/12 ED Goto refractor*

* Fukui City Observatory, Fukui

PARKER, Donald C (DPk) Miami, FL, USA

18 Sets of CCD Images + 2 Drawings (16, 18*, 21, 25, 27, 30 December 2003)

f/55, 5941cm F/6 spec equipped with an ST-9XE/

*f/2241cm spec with a ToUcam + 545, 60041cm spec

PEACH, Damian A (DPc) Loudwater, Buckinghamshire, UK

7 Sets of CCD Images (17, 18 December 2003)

f/3128cm SCT with an ATK-1HS

  

PELLIER, Christophe (CPl) Bruz, Ille-et-Vilaine, France

4 Sets of CCD Images (16, 17 December 2003)

35cm SCT with a modified B&W ToUcam Pro

SIEGEL, Elisabeth (ESg) Malling, Danmark

4 Drawings (18, 19, 22, 30 December 2003) 27020cm F/10 SCT

TATUM, Randy (RTm) Richmond, VA, USA

2 CCD Images (21, 25 December 2003) 25cm spec (F/12) with a ToUcam

  

TEICHERT, Grard (GTc) Hattstatt, France

3 Drawings (17, 24, 29 December 2003) 33028cm SCT

  

VALIMBERTI, Maurice P (MVl) Melbourne, Australia

1 CCD Image (27 December 2003)

f/4135cm SCT with a ToUcam Pro

  

Van Der VELDEN, Erwin (EVl) Brisbane, Australia

8 CCD Images (16, 18, 19, 21, ~23, 29*, 31* December 2003)

f/3120cm SCT +* f/2923cm SCT with a Vesta Pro modified

WARELL, Johan (JWr) Tcuson, AZ, USA

       5 Sets of CCD Images + 1 Drawing (18, 21, 21*, 22 December 2003)

f/2425cm SCT with a ToUcam +26025cm SCT*

f/2425cm SCT with a ToUcam +26025cm SCT*

 

WILLIAMSON, Thomas E (TWs) Alburquerque, NM, USA

2 Set of CCD Images (17, 20 December 2003)

f/5020cm spec with a Philips ToUcam

 

 

 

December 2003 Dust (bis)

16 Dec (λ=317Ls): From around 14 Dec, the energy vector of the yellow cloud aloft was southward perhaps due to the warming of the equatorial region at this season, and so the Coriolis force bent its vector to the east. As reported , on 15 Dec, there occurred strong disturbances near at Argyre and Dia, and succeedingly the images made by PARKER (DPk) on 16 Dec (λ=317Ls) at ω=019W, 030W, 041W show an abrupt large development at the east side to Noachis. Usually at night the stratosphere goes down to the ground so near that the convection does not occur, and so the early stage of dust does not easily move, but if the condition of catastrophe remains to be latent, the dust disturbance revives next morning and gradually the lifted dust should obey the deflecting force. The aspect of dust distribution on 16 Dec taken by DPk suggests a good deal of residual dusts at night. We thus consider the condition of dust disturbance was propagated to the east, and at first it caused a dust disturbance at the western corner of Deucalionis Regio (the preferable place which is known as one causing dust disturbance since 1956). Then as the planet rotated, several dust successively occurred in a series at Noachis. As the TES dust image on 16 Dec show, the disturbance cores occurred discretely at the west of Argyre and Dia. These two however might have been the residuals of the cores of the day before. BEISH (JBs) at ω=031W also reported a residual core at Eos. The west side was dull, as shown by Van der Velden (EVl) at ω=165W, and by KUMAMORI (Km) at ω=159W, 177W, dusts west end was near at Dia or around Ω=090W. IWASAKI (Iw) visually confirmed this at ω=166W and chased until ω=185W.

Interestingly PELLIER (CPl) caught a new rise of the dust at the east end of Deucalionis R at Martian dawn at ω=284W, 289W, (300W), 302W, 17 hrs after the observations of DPk. Apparently no change has occurred at the Hellas region, but was shown there a water condensate preceding the rise of dust.

The bright band where several cores rose in the DPk 16 Dec case looks different from the belt visible in early 2003, and reminiscent of the 1956 dust route as taken by W S FINSEN at the Union Observatory on 29 and 30 August 1956, and so the settlement in future should be said interesting. The early 2003 aspect of Noachis was akin to the 1924 case (except for the widening of M Serpentis caused by the 4 July 2003 dust disturbance), while the Dec 2003 dust may cause another feature.

 

17 Dec (λ=317Ls~318Ls): On 17 Dec, in the US, WILLIAMSON (TWs) provided the image at ω=034W (01:31GMT) where the longitude Ω=300W was on the eastern limb and we cannot judge about the east end of Deucalionis R, but the limb side was bright and this area looked separated from another bright part near Argyre at Ω=000W. On the other hand, the area of S Meridiani was largely covered by dust to the extent that the dark markings looked obscured. In Japan, Km took an image at ω=087W, and MURAKAMI (Mk) visually observed at ω=142W to check the west end of the cloud. CPl chased the morning dust (after spending a night) from 17:40 to 18:59GMT (ω=068W~287W), but the angle was in short to detect the Deucalionis R cloud, and at least there was no explicit extension to Hellas except for a procession of condensate.

18 Dec (λ=318Ls): DPk visually observed at ω=356W and ω=016W where he checked the yellow cloud at the Noachis and Argyre areas. Furthermore it was impossible to see S Meridiani because of the presence of the dust covering. He also took an image by ToUcam at ω=030W. Comparison with the image at the same angle made on 16 Dec suggests that the airborne dust prevailed over the higher altitude. GRAFTON (EGf) also took images at ω=004W (00:17GMT) and showed the aspect of the dust at the east end of Deucalionis R: Its bright core extended southward along Yaonis Fr, but never invaded Hellas. His images show that the area around Meridiani S has been dim due to a covering of the dust. WARELL (JWr) took the area round Argyre at ω=060W. Moving to Oceania, EVl showed at ω=132W that the dust invaded to the south of M Sirenum, while a large area around Aonius S was quite outside the dust.

The eastern front of dust at the Deucalionis R was visually observed 20 hours later by BIVER (NBv) at ω=284W, 296W (20:17GMT) at the morning side, and was shown to remain the same. KOVACEVICH (ZKv) also showed at ω=286W that bright dust core was along the Yaonis Fr. The dust thus seemed to begin to survive at night. SIEGEL (ESg) observed earlier at ω=236W: Hellas looked bright, but Yaonis Regio was not yet present inside the disk. The terminator was bright through Wr#47.

 

19 Dec (λ=319Ls): EGf took images at ω=355W and featured the dust core at the east end of Deucalionis R. The aspect of the dust expansion around Yaonis R is reminiscent of the dust disturbance observed on 7 July 2003, but slightly of smaller scale. TES showed the dust gave a large expansion at the south of Noachis. The west front of the dust was observed by EVl at ω=122W: it looks somewhat more retreated than on 17 Dec. There was no image which showed the dust at the morning terminator. ESg observed at ω=264W that Hellas was bright near the terminator (regarded Hellas cloud).

20 Dec (λ=319Ls): EGf and TWs made images at ω=350W and ω=355W respectively. Some cores were checked which are different than those on the day before and the images showed a southward expansion at Noachis. KARRER (MKr) took an image one round after at ω=242W: There seems a morning condensate over Hellas.

21 Dec (λ=320Ls): EGf took images at ω=334W, and then DPk at ω=337W, 339W and 357W: A dust disturbance was induced at the north-western corner of Hellas (at the first time, shown also on the TES image). JWr took at ω=014W, 029W and showed how the dust at Noachis changed from the configuration on 20 Dec. The west front development was chased by Km, Mo and EVl from ω=059W to 134W (Mk also did visually from ω=090W to 120W). There was no expansion due to the eastward deflection force. They all show however an existence of a conspicuous bright belt from Argyre to Thaumasia (all ccd and also to the naked eye of Mk). TATUM (RTm) shot an image of Hellas one turn later.

 

22 Dec (λ=320Ls): TESs 2 oclock image shows that the disturbance inside Hellas diminished and the southward vector at Noachis has sent the dust to the south circumpolar region. And thus the settling down of the Dec 2003 dust event is suggested. JWrs images at ω=347W, 012W show the dust from Noachis to its south (images are however too small and too declined). The west end of the dusty area was checked by EVl at ω=092W, and by MIYAZAKI (My) at ω=118W, 140W. Visually Mk observed at ω=081W, 090W, and 100W. The boundary of the dust was clearer than the day before.

 

23 Dec (λ=321Ls): TES shows another small disturbance inside Hellas at the west-southern part but no observations from the US. At the Asia-Oceania, Km, Ak, Mo, My, and EVl got ccd images, and Mk and Iw observed visually. The angles were from ω=045W to 117W. Important was that another dust was lifted near Chryse, and every observation made earlier recorded this. According to TES, around from 19 Dec, there was floated an airborne dust over Arabia and Eden, but its dissipation made a concentration of dust at Chryse on 23 Dec. On the next day it was weakened, but it repeated the process until around 26 Dec.

 

24 Dec (λ=322Ls): BUNGE (RBg) made a drawing at ω=318W of Hellas dust at its north, but TES shows it at south. My obtained a clearer image at ω=088W, and shows a dust distribution from Noachis down to the NH. The vagueness of the area of Solis L and the curious enlargement of the dark area of Aurorae S were also well shown. Argyre looks as a reservoir of dust, but TES does not show it and hence the dust must have been quite near the ground or it was due to the dusty ground reflection.

 

25 Dec (λ=322Ls): DPk took Hellas near the center at ω=300W, 304W and shows a dust distribution from Hellas to Ausonia. Zea L and other dark markings are however shown there. After about six hours, Km took by R light at ω=026W and showed that there was a dust expansion from Chryse to the west part of Deucalionis R. This was also visually seen (Mn: ω=037W, 046W), but nowhere any bright core was found. This was also clearly seen on the next images taken by Km on

26 Dec (λ=323Ls) at ω=021W(15:45JST), 034W: Certainly an expansion of Chryse dust. S Meridiani however slightly recovered, and M Serpentis also showed its wide and darkened aspect. Kms next images on

27 Dec (λ=323Ls) at ω=019W, ω=038W also show similar situation. On this day DPk produced images from ω=268W to 287W. The area around of Hellas also recovered, and M Hadriacum is shown as well as Zea L. The nph is thick. VALIMVERTI (MVl)s image at ω=071W also shows the thick nph. On the TES image no core of dust is found except one near Aram which is also seen on Kms images. Argyre must be ground lit.

 

28 Dec (λ=324Ls): TES does not show any more the dust disturbance, while on the images made by Ak at ω=342W, 348W, 001W and by Km at ω=029W, 007W, 039W, area around S Meridiani looks again obscure. This area becomes cleared on TES on 31 Dec.

 

29 Dec (λ=324Ls): Clearer images were obtained by EVl at ω=027W, and by My at ω=033W, and they show how the area from Aram to the western half of Margaritifer S is obscured by dust (Oxia P is barely seen however). M Serpentis is no longer seen on these images, but the dark band from M Serpentis to M Erythraeum has become dominant. The images by LAU (CLa) at ω=060W and 070W show the area including unusual Aurorae S.

 

30 Dec (λ=325Ls): Mys image ω=021W gives a good comparison with the image made the day before. The area around Argyre looks morning misty. Noachis was caught by Mo at ω=002W ~ 058W, and by Km at ω=003W ~ 061W. On Kms images S Sabaeus is bar-like, while Mos images show Meridiani S. Visually Mn observed Sabaeus S was dark but not detailed more than bar-like (chased from ω=350W to 049W). Argyre was not present on Mos B images (though clear in R and G). Visually the light Argyre was seen around from ω=019W, but Mn judged it was whitish. As seen on Mos images, the dark band on Noachis was not complete at the area near M Serpentis. ESg observed at ω=115W, and saw clearly Solis L: the south circumpolar area was largely light and its boundary was sharply defined.

 

31 Dec (λ=326Ls): The air borne dust around Aram was shown on the images by EVl at ω=016W, and by CLa at ω=036W. They both show otherwise a mist-like morning matter near Argyre. As far as we judge from the TES images, strong dust disturbances have dissipated.

 

Remark: The southern summer solstice occurs at λ=270Ls, and autumnal equinox at λ=360Ls. In summer, the air mass which is warmed up at the south polar region goes down to the direction of the NH and the easterly will blow on the SH. On the other hand, in the fall, the equatorial region is warmed up and the air mass will go up toward the south polar region. In this sense, the season around λ=320Ls is ambivalent, while the present case of the motion vector of the airborne dust suggests that the pattern of the air mass motion was akin to the autumnal case. In fact this case the westerlies worked on the SH and at the final stage the dust went to the south circumpolar region. Note however the westerlies work on the vector of the air mass from morning to evening, and at night the convection does not work since the stratosphere goes down to near the ground. When the air mass has latent inertia to raise a catastrophe as the convection begins to work on the succeeding day, another catastrophe will be renewed, and will also make another series of resonance. So if we have a series of cores of dust we should first treat the leftmost core as an advanced original and followers are newer. Any disturbance core does not move so rapidly, but renews next day and sometimes disappears or makes a quantum jump at another place.

 If the dust is an autumnal type, the air mass tends to be cooled, and so it may not develop globally.

Impressive images: In spite of the small angular diameter, excellently detailed images were obtained by PEACH (DPc) at the angles where the dust did not work on 18 Dec (λ=318Ls) at ω=239W~263W: The phase angle was ι=42, and the detailed M Cimmerium looks darker at the northern half. The spc is also clearly defined. DPk also gave excellent images from the similar angles on 30 Dec (λ=325Ls) at ω=226W, 229W, detailed though δ=8.5": A ground lit area at Eridania is shot.

 


T

he next issue shall treat the observations made in the First half of January 2004 from 1 January (λ=326Ls) to 15 January 2004 (λ=334Ls, δ=7.6").


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