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st Report:
The CMO/OAA Observations made
during a fortnight period
from
16 December
2003 (317°Ls)
to
31 December 2003 (326°Ls)
An OAA Mars Section article to be published in CMO #286 (10
January 2004 issue)
Masatsugu MINAMI, Director of the OAA Mars Section
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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=314°Ls) (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=317°Ls) to 31 Dec 2003
(λ=326°Ls). The apparent diameter δ went down from 9.6" to
8.5", and the phase angle ι was 42°. The central latitude φ was
26°S, and so the southern hemisphere was well observed. The apparent declination
came back to the celestial equator and so the planet shined higher. In
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he
observers contributed this time were as follows (a total of 27 observers):
AKUTSU, Tomio (Ak) Karasuyama,
7 Sets of CCD Images (+2 IR images)(23, 28, 30 December 2003)
f/33×32cm spec with a Bitran BJ-41L
BEISH,
Jeffrey D (JBs)
1 Drawing (16 December 2003) 590×41cm F/6.9
speculum
BIVER,
Nicolas (NBv)
2 Colour Drawings (18 December
2003)
510×26cm speculum
BUNGE, Robert
(RBg)
1 Drawing (24 December 2003) 210×10cm spec
FRASSATI, Mario (MFr)
Crescentino (VC), Italia
1 Drawing (23 December 2003) 400×20cm SCT
GRAFTON,
Edward A (EGf)
4 CCD Images (18, ~20, 21 December
2003)
f/39×35cm
SCT with an ST-5C
IWASAKI, Tohru (Iw)
9 Drawings (16, 21, 23, 28
December 2003)
400×21cm speculum
KARRER,
Michael (MKr) St Radegund, Österreich
1 CCD Image (20 December 2003)
f/35×18cm
Meade Refraktor with a
ToUcam
KOVACEVIC, Zkatko F (ZKv)
1 CCD Image (18 December 2003)
f/20×20cm STC with a ToUcam
KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan
27 CCD Images (16, 17#, 21#,
23#, 25#, ~27#
, 28, 30 December 2003)
f/84×20cm Dall-Kirkham & f/40×60cm Cass# with a ToUcam
#
LAU, Canon (CLa) Hong-Kong
4 CCD Images (25, 29, 31 December
2003)
f/32×35cm
SCT with a ToUcam
MELILLO,
Frank J (FMl)
2 Red CCD Images (28, 30 December 2003)
20cm SCT with a Starlight Xpress
MX5
MINAMI, Masatsugu (Mn)
Fukui,
12 Drawings (22, 25, 28, 30 December
2003)
480, 400×20cm F/12 ED Goto refractor*
*
6 CCD Images (22, ~24, 29, 30
December 2003)
40cm F/6 speculum with ToUcam
MORITA, Yukio (Mo) Hatsuka-ichi,
16 Sets of CCD Images (21, 23, 30
December 2003)
25cm spec equipped
with an ST-5C
MURAKAMI, Masami (Mk)
19
Drawings (16, 17, 21, 22, 23, 24, December 2003)
320×20cm speculum
NAKAJIMA, Takashi (Nj) Fukui,
9 Drawings (28, 30 December
2003)
480, 400×20cm F/12
ED Goto refractor*
*
PARKER,
Donald C (DPk)
18 Sets of CCD Images + 2 Drawings
(16, 18*, 21, 25, 27, 30 December 2003)
f/55, 59×41cm F/6
spec equipped with an ST-9XE/
*f/22×41cm spec with a ToUcam + 545, 600×41cm spec
PEACH, Damian A (DPc) Loudwater,
7 Sets of CCD Images (17, 18
December 2003)
f/31×28cm SCT
with an ATK-1HS
PELLIER, Christophe (CPl) Bruz,
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) 270×20cm F/10
SCT
TATUM, Randy
(RTm)
2 CCD Images (21, 25 December 2003) 25cm spec (F/12) with a ToUcam
TEICHERT, Gérard (GTc)
3 Drawings (17, 24, 29 December
2003) 330×28cm SCT
VALIMBERTI,
Maurice P (MVl)
1 CCD Image (27 December 2003)
f/41×35cm
SCT with a ToUcam Pro
Van Der
VELDEN, Erwin (EVl)
8 CCD Images (16, 18, 19, 21, ~23,
29*, 31* December 2003)
f/31×20cm
SCT +* f/29×23cm SCT with a Vesta Pro modified
WARELL, Johan
(JWr)
5 Sets of CCD Images + 1 Drawing (18, 21, 21*, 22 December 2003)
f/24×25cm
SCT with a ToUcam +260×25cm SCT*
f/24×25cm
SCT with a ToUcam +260×25cm SCT*
WILLIAMSON,
Thomas E (TWs)
2 Set of CCD Images (17, 20 December
2003)
f/50×20cm spec with a Philips ToUcam
December
2003 Dust (bis)
16 Dec (λ=317°Ls): 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=317°Ls) at ω=019°W, 030°W, 041°W 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=031°W also reported a residual core at
Eos. The west side was dull, as shown by Van der Velden
(EVl) at ω=165°W, and by KUMAMORI (Km) at ω=159°W, 177°W, dust’s west end was near at
Dia or around Ω=090°W. IWASAKI (Iw) visually
confirmed this at ω=166°W and chased until ω=185°W.
Interestingly PELLIER (CPl) caught a new rise of the dust at the east end of Deucalionis R
at Martian dawn at ω=284°W, 289°W, (300°W), 302°W, 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=317°Ls~318°Ls): On 17 Dec, in the
US, WILLIAMSON (TWs) provided the
image at ω=034°W (01:31GMT) where the longitude
Ω=300°W 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=000°W. On the other hand, the area of
18 Dec (λ=318°Ls): DPk visually observed at ω=356°W and ω=016°W where he checked
the yellow cloud at the Noachis and Argyre areas. Furthermore it was impossible
to see
The eastern front of dust at the Deucalionis R was
visually observed 20 hours later by BIVER (NBv)
at ω=284°W, 296°W (20:17GMT) at the morning
side, and was shown to remain the same. KOVACEVICH (ZKv) also showed at ω=286°W 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=236°W:
19 Dec (λ=319°Ls): EGf took images at ω=355°W 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=122°W: 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=264°W that Hellas was bright near the terminator (regarded
20 Dec (λ=319°Ls): EGf and TWs made images
at ω=350°W and ω=355°W 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=242°W: There seems a morning condensate
over
21 Dec (λ=320°Ls): EGf took images at ω=334°W, and then DPk at ω=337°W, 339°W and 357°W: A dust disturbance was induced at
the north-western corner of
22 Dec (λ=320°Ls): TES’s 2 o’clock image shows that the disturbance inside
23 Dec (λ=321°Ls): TES shows another
small disturbance inside Hellas at the west-southern part but no observations
from the
24 Dec (λ=322°Ls): BUNGE (RBg) made a drawing at ω=318°W of
25 Dec (λ=322°Ls): DPk took Hellas near the center at ω=300°W, 304°W and shows a dust
distribution from
26 Dec (λ=323°Ls) at ω=021°W(15:45JST), 034°W: Certainly an
expansion of Chryse dust.
27 Dec (λ=323°Ls) at ω=019°W, ω=038°W also show similar
situation. On this day DPk produced
images from ω=268°W to 287°W. The area around of
28 Dec (λ=324°Ls): TES does not show any more the dust
disturbance, while on the images made by Ak
at ω=342°W, 348°W, 001°W and by Km at ω=029°W, 007°W, 039°W, area around S
Meridiani looks again obscure. This area becomes cleared on TES on 31 Dec.
29 Dec (λ=324°Ls): Clearer images were
obtained by EVl at ω=027°W, and by My at ω=033°W, and they show how the area from
30 Dec (λ=325°Ls): My’s image ω=021°W 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=002°W ~ 058°W, and by Km at ω=003°W ~ 061°W. On Km’s images S Sabaeus is bar-like, while Mo’s images show Meridiani S. Visually Mn observed Sabaeus S was dark but not detailed more than bar-like
(chased from ω=350°W to 049°W). Argyre was not present on Mo’s B images (though clear in R and
G). Visually the light Argyre was seen around from ω=019°W, but Mn judged it was whitish. As seen on Mo’s images, the dark band on Noachis
was not complete at the area near M Serpentis. ESg observed at
ω=115°W, and saw clearly Solis L: the south circumpolar area was largely
light and its boundary was sharply defined.
31 Dec (λ=326°Ls): The air borne dust around
Remark: The southern summer
solstice occurs at λ=270°Ls, and autumnal equinox at λ=360°Ls. 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=320°Ls 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=318°Ls) at ω=239°W~263°W: 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=325°Ls) at ω=226°W, 229°W, detailed though
δ=8.5": A ground lit area at Eridania is shot.
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he next
issue shall treat the observations made in the First half of January 2004 from 1 January (λ=326°Ls)
to 15 January 2004 (λ=334°Ls, δ=7.6").
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