Weather
Statistics
Tau Meter Plots:
Below are 3d plots showing the zenith opacity as a function of time. Blank
fields indicate no data available for that month. *12
Meter Tipper on loan to GMT for testing in Chile.
12 Meter:
SMT:
Report summarizing
SMT T225 GHz statistics in
pdf.
SMT Weather Statistics
Following standard practice, SMT uses an room temperature mixer receiver system,
centered on the 1.3 mm window (225 GHz), to monitor the optical depth, tau(225),
of the atmosphere every half hour.
Generally speaking, the 1.3mmJT receivers is useful for T225 GHz <
0.30; the 345 GHz receiver needs T225 GHz < 0.15; and in order for
490 GHz to be useful you need T225 GHz < 0.10.
The percentage of time for which T225 GHz is lower than the
indicated value.
2007-2008
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
0.0 |
1.8 |
26.8 |
74.9 |
| November |
GIF |
GIF |
0.9 |
1.1 |
11.5 |
59.7 |
| December |
GIF |
GIF |
5.3 |
11.0 |
46.3 |
75.0 |
| January |
GIF |
GIF |
1.7 |
8.5 |
22.6 |
68.9 |
| February |
GIF |
GIF |
1.2 |
5.2 |
12.6 |
74.1 |
| March |
GIF |
GIF |
6.8 |
15.6 |
59.3 |
94.9 |
| April |
GIF |
GIF |
|
|
|
|
| May |
GIF |
GIF |
|
|
|
|
|
June |
GIF |
GIF |
|
|
|
|
2006-2007
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
6.5 |
11.4 |
33.9 |
50.7 |
| November |
GIF |
GIF |
5.1 |
9.9 |
58.1 |
92.9 |
| December |
GIF |
GIF |
13.6 |
19.2 |
43.8 |
67.7 |
| January |
GIF |
GIF |
8.1 |
12.0 |
40.3 |
58.1 |
| February |
GIF |
GIF |
3.5 |
8.9 |
42.0 |
67.9 |
| March |
GIF |
GIF |
6.0 |
9.8 |
37.0 |
76.5 |
| April |
GIF |
GIF |
0.6 |
1.7 |
19.0 |
64.5 |
| May |
GIF |
GIF |
0.0 |
0.0 |
3.9 |
42.2 |
|
June |
GIF |
GIF |
0.0 |
0.0 |
2.0 |
16.4 |
2005-2006
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
0.4 |
1.9 |
25.3 |
62.4 |
| November |
GIF |
GIF |
18.2 |
25.8 |
56.7 |
89.4 |
| December |
GIF |
GIF |
10.9 |
17.1 |
46.2 |
85.4 |
| January |
GIF |
GIF |
11.0 |
22.4 |
63.0 |
89.4 |
| February |
GIF |
GIF |
18.0 |
28.6 |
64.1 |
86.5 |
| March |
GIF |
GIF |
4.6 |
12.8 |
41.8 |
68.5 |
| April |
GIF |
GIF |
1.1 |
4.7 |
54.3 |
77.7 |
| May |
GIF |
GIF |
0.2 |
0.6 |
25.5 |
75.3 |
|
June |
GIF |
GIF |
0.0 |
0.1 |
5.8 |
23.7 |
2004-2005
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
3.6 |
6.0 |
27.3 |
68.8 |
| November |
GIF |
GIF |
10.3 |
15.5 |
44.7 |
71.3 |
| December |
GIF |
GIF |
14.6 |
20.0 |
58.7 |
84.0 |
| January |
GIF |
GIF |
7.1 |
11.9 |
35.6 |
64.2 |
| February |
GIF |
GIF |
3.8 |
5.6 |
25.4 |
51.5 |
| March |
GIF |
GIF |
7.0 |
10.5 |
39.7 |
73.9 |
| April |
GIF |
GIF |
6.8 |
10.8 |
45.9 |
89.4 |
| May |
GIF |
GIF |
1.8 |
3.6 |
19.0 |
71.7 |
|
June |
GIF |
GIF |
1.3 |
2.8 |
17.2 |
55.8 |
2003-2004
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
0.3 |
2.2 |
27.8 |
57.7 |
| November |
GIF |
GIF |
12.3 |
20.1 |
52.4 |
73.4 |
| December |
GIF |
GIF |
14.2 |
25.0 |
52.1 |
79.9 |
| January |
GIF |
GIF |
1.0 |
2.3 |
32.3 |
72.2 |
| February |
GIF |
GIF |
14.1 |
21.6 |
53.4 |
83.1 |
| March |
GIF |
GIF |
5,2 |
11.6 |
44.0 |
71.5 |
| April |
GIF |
GIF |
5.0 |
10.3 |
44.3 |
75.7 |
| May |
GIF |
GIF |
0.8 |
2.6 |
37.2 |
80.0 |
|
June |
GIF |
GIF |
1.3 |
3.1 |
21.0 |
58.5 |
2002-2003
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
2.2 |
4.2 |
20.0 |
55.5 |
| November |
GIF |
GIF |
8.4 |
13.8 |
47.6 |
76.0 |
| December |
GIF |
GIF |
7.7 |
14.7 |
49.7 |
78.4 |
| January |
GIF |
GIF |
7.1 |
15.3 |
53.2 |
87.1 |
| February |
GIF |
GIF |
7.4 |
12.4 |
33.4 |
61.5 |
| March |
GIF |
GIF |
13.0 |
18.3 |
45.8 |
74.0 |
| April |
GIF |
GIF |
5.8 |
11.1 |
52.4 |
89.9 |
| May |
GIF |
GIF |
3.2 |
6.2 |
31.6 |
71.6 |
|
June |
GIF |
GIF |
0.8 |
1.2 |
9.7 |
58.0 |
2001-2002
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
2.0 |
4.6 |
23.3 |
54.6 |
| November |
GIF |
GIF |
3.4 |
4.6 |
19.1 |
60.6 |
| December |
GIF |
GIF |
19.3 |
29.4 |
59.3 |
89.3 |
| January |
GIF |
GIF |
11.4 |
16.9 |
43.9 |
70.5 |
| February |
GIF |
GIF |
14.4 |
25.3 |
60.1 |
90.4 |
| March |
GIF |
GIF |
15.5 |
24.5 |
68.8 |
90.3 |
| April |
GIF |
GIF |
1.5 |
4.7 |
27.5 |
77.4 |
| May |
GIF |
GIF |
5.3 |
9.0 |
33.9 |
85.3 |
|
June |
GIF |
GIF |
0.1 |
0.2 |
6.7 |
35.8 |
2000-2001
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
0.8 |
2.6 |
18.7 |
38.2 |
| November |
GIF |
GIF |
8.5 |
15.7 |
59.2 |
83.4 |
| December |
GIF |
GIF |
7.6 |
15.6 |
52.9 |
76.4 |
| January |
GIF |
GIF |
15.3 |
22.8 |
55.8 |
72.2 |
| February |
GIF |
GIF |
5.1 |
9.6 |
50.7 |
76.5 |
| March |
GIF |
GIF |
3.8 |
9.4 |
49.5 |
84.8 |
| April |
GIF |
GIF |
5.5 |
11.8 |
50.3 |
75.5 |
| May |
GIF |
GIF |
0.4 |
1.2 |
19.3 |
69.0 |
|
June |
GIF |
GIF |
0.3 |
1.0 |
10.3 |
45.1 |
1999-2000
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
8.2 |
20.8 |
61.0 |
86.0 |
| November |
GIF |
GIF |
9.0 |
16.0 |
68.8 |
96.4 |
| December |
GIF |
GIF |
11.9 |
22.1 |
65.5 |
77.6 |
| January |
GIF |
GIF |
14.4 |
21.8 |
52.6 |
84.9 |
| February |
GIF |
GIF |
10.1 |
20.8 |
57.8 |
86.2 |
| March |
GIF |
GIF |
7.3 |
15.3 |
56.7 |
84.6 |
| April |
GIF |
GIF |
6.0 |
10.7 |
59.5 |
97.0 |
| May |
GIF |
GIF |
0.7 |
2.9 |
27.0 |
78.4 |
|
June |
GIF |
GIF |
na |
na |
na |
na |
1998-1999
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
4.2 |
9.3 |
43.8 |
68.1 |
| November |
GIF |
GIF |
6.0 |
13.5 |
54.2 |
89.0 |
| December |
GIF |
GIF |
12.1 |
15.3 |
44.6 |
74.2 |
| January |
GIF |
GIF |
20.0 |
28.3 |
67.5 |
96.2 |
| February |
GIF |
GIF |
25.9 |
30.4 |
66.4 |
96.3 |
| March |
GIF |
GIF |
14.8 |
25.6 |
73.2 |
92.7 |
| April |
GIF |
GIF |
14.2 |
21.9 |
55.1 |
87.5 |
| May |
GIF |
GIF |
1.8 |
4.0 |
41.8 |
82.4 |
|
June |
GIF |
GIF |
0.1 |
1.1 |
26.5 |
42.5 |
1997-1998
|
Month |
Tau Data |
Tau Stats |
<0.06 |
<0.075 |
<0.15 |
<0.30 |
| October |
GIF |
GIF |
13.6 |
20.6 |
45.7 |
73.7 |
| November |
GIF |
GIF |
16.2 |
26.0 |
54.9 |
81.8 |
| December |
GIF |
GIF |
27.4 |
32.9 |
56.9 |
63.1 |
| January |
GIF |
GIF |
16.9 |
30.4 |
60.3 |
83.7 |
| February |
GIF |
GIF |
6.7 |
13.1 |
46.3 |
70.8 |
| March |
GIF |
GIF |
8.9 |
16.1 |
47.8 |
72.2 |
| April |
GIF |
GIF |
6.9 |
14.0 |
51.4 |
86.3 |
| May |
GIF |
GIF |
4.8 |
11.2 |
51.4 |
84.7 |
|
June |
GIF |
GIF |
0.6 |
2.4 |
30.3 |
76.4 |
Priority Observing:
In order to exploit the best atmospheric conditions, the SMT has implemented
priority observing arrangements. The scheme functions as follows: Whenever
tau(225) reaches a value of 0.06 or less, the normal observing program (at 1.3 mm
or 0.87 mm) is replaced by a priority proposal, which could be carried out only
in the best weather. When tau(225) increases to more than 0.075 the normal
observing program is restarted. The
priority observing system has functioned well and will be continued.
Raw Weather
Data |