Atacama Desert, Dome A, and Mauna Kea Transmissivity Plots


The following PostScript files are the result of using Erich Grossman's AT code, modified to use a Voigt-function approximation for the line profile, to calculate atmospheric transmissivities for the Atacama Desert and Mauna Kea, from 1 micron to 1000 microns.

Base temperatures at the two site are assumed to be 263 K and 275 K, respectively for an Atacama winter and a Mauna Kea summer (when precipitable water vapor levels are at seasonal lows). Zenith angle of pointing is 45 degrees (airmass = 1.414). The plots contain data for the 25%, 50%, and 75% quartiles for precipitable water vapor, which are, respectively, 0.68 mm [solid line], 1.00 mm [dashed line], and 1.60 mm [dotted line] for the Atacama Desert and 1.70 mm [solid line], 2.90 mm [dashed line], and 5.9 mm [dotted line] for Mauna Kea.

The format of the gzipped file names is "atwin_[a-j]t.ps.gz" for the Atacama winter and "mksum_[a-j]t.ps.gz" for the Mauna Kea summer. The letter index represents a wavelength regime, as detailed in the table below. All files have a resolution of R=1000.

Wavelength Ranges:

Wavelength Index   Range (microns):
       a           1.-2.
       b           2.-4.
       c           4.-8.
       d           8.-16.
       e           16.-32.
       f           32.-64.
       g           64.-128.
       h           128.-256.
       i           256.-512.
       j           512.-1024.

The following is a list of the individually downloadable PS files and their respective file sizes. All of the Atacama Desert plots can also be found in a 126 KB gzipped tar file while the Mauna Kea plots can be found in a 121 KB gzipped tar file.

Transmissivity Plots:

Atacama Desert Winter: -rw-r--r-- 1 kachun 52758 Jun 4 15:05 atwin_at.ps.gz -rw-r--r-- 1 kachun 54605 Jun 4 15:06 atwin_bt.ps.gz -rw-r--r-- 1 kachun 53090 Jun 4 15:06 atwin_ct.ps.gz -rw-r--r-- 1 kachun 51921 Jun 4 15:06 atwin_dt.ps.gz -rw-r--r-- 1 kachun 52926 Jun 4 15:06 atwin_et.ps.gz -rw-r--r-- 1 kachun 51120 Jun 4 15:07 atwin_ft.ps.gz -rw-r--r-- 1 kachun 54036 Jun 4 15:08 atwin_gt.ps.gz -rw-r--r-- 1 kachun 57528 Jun 4 15:09 atwin_ht.ps.gz -rw-r--r-- 1 kachun 55104 Jun 4 15:05 atwin_it.ps.gz -rw-r--r-- 1 kachun 54705 Jun 4 15:05 atwin_jt.ps.gz Figure caption: Sky transmissivity for the Atacama Desert in winter calculated with the AT code at a resolution of R=1000 and for a zenith angle of 45 degrees. Lines are for the 25%, 50%, and 75% quartile levels of precipitable water vapor, respectively at 0.68 mm (dotted line), 1.00 mm (dashed line), and 1.60 mm (solid line). Dome A: -rw-r--r-- 1 kachun 50321 Sep 11 15:07 domea_ijt.ps.gz Figure caption: Sky transmissivity for the Antarctic Dome A site calculated with the AT code at a resolution of R=1000 and for a zenith angle of 45 degrees. Lines are for the 25%, 50%, and 75% quartile levels of precipitable water vapor, respectively at 0.050 mm (dotted line), .100 mm (dashed line), and 1.50 mm (solid line). Mauna Kea Summer: -rw-r--r-- 1 kachun 54129 Jun 4 15:33 mksum_at.ps.gz -rw-r--r-- 1 kachun 55409 Jun 4 15:33 mksum_bt.ps.gz -rw-r--r-- 1 kachun 52660 Jun 4 15:33 mksum_ct.ps.gz -rw-r--r-- 1 kachun 53008 Jun 4 15:34 mksum_dt.ps.gz -rw-r--r-- 1 kachun 52757 Jun 4 15:34 mksum_et.ps.gz -rw-r--r-- 1 kachun 52387 Jun 4 15:34 mksum_ft.ps.gz -rw-r--r-- 1 kachun 54496 Jun 4 15:37 mksum_gt.ps.gz -rw-r--r-- 1 kachun 51902 Jun 4 15:37 mksum_ht.ps.gz -rw-r--r-- 1 kachun 54169 Jun 4 15:38 mksum_it.ps.gz -rw-r--r-- 1 kachun 60268 Jun 4 15:38 mksum_jt.ps.gz Figure caption: Sky transmissivity for Mauna Kea in summer calculated with the AT code at a resolution of R=1000 and for a zenith angle of 45 degrees. Lines are for the 25%, 50%, and 75% quartile levels of precipitable water vapor, respectively at 0.68 mm (dotted line), 1.00 mm (dashed line), and 1.60 mm (solid line).

Sky Thermal Emission Plots:

Dome A:
-rw-r--r--  1 kachun      55354 Sep 11 15:15 domea_ije.ps.gz
Atacama Desert Winter:
-rw-r--r--  1 kachun      53211 Sep 11 15:17 atwin_ije.ps.gz
Mauna Kea Summer:
-rw-r--r--  1 kachun      52623 Sep 11 15:16 mksum_ije.ps.gz

Figure caption: Sky thermal emission for Dome A, the Atacama
Desert, and Mauna Kea calculated with the AT code at a resolution of
R=1000 and for a zenith angle of 45 degrees.  Lines are for the 25%,
50%, and 75% quartile levels of precipitable water vapor, which are
respectively at 0.050 mm (dotted line), 0.100 mm (dashed line), and 1.50
mm (solid line) for Dome A; 0.68 mm (dotted line), 1.0 mm (dashed line),
and 1.6 mm (solid line) for Atacama; 1.7 mm (dotted line), 2.9 mm (dashed
line), and 5.9 mm (solid line) for Mauna Kea.

Sky Emission Comparison with Gemini Figures:

Mauna Kea:
-rw-r--r--  1 kachun   casa        54007 Apr 14 00:34 mk1_2_3.ps.gz
-rw-r--r--  1 kachun   casa        48015 Apr 14 18:05 mk_at0.ps.gz
-rw-r--r--  1 kachun   casa        49840 Apr 14 18:05 mk_at1.ps.gz
-rw-r--r--  1 kachun   casa        44350 Apr 14 18:06 mk_at2.ps.gz
-rw-r--r--  1 kachun   casa       187848 Apr 14 17:55 mk_mod0.ps.gz
-rw-r--r--  1 kachun   casa       165487 Apr 14 17:57 mk_mod1.ps.gz
-rw-r--r--  1 kachun   casa       149497 Apr 14 18:08 mk_mod2.ps.gz

Figure caption: Sky thermal emission for Mauna Kea calculated with
the AT code at a resolution of R=1000, and for 1., 2., and 3. airmasses.
Water vapor is at 1.00 mm, and we are assuming a uniform sky temperature
of 285 K.  Also transmittance plots calculated with AT (mk_at0.ps, mk_at1.ps,
mk_at2.ps) and MODTRAN (mk_mod0.ps, mk_mod1.ps, mk_mod2.ps) over the
wavelength range 1-40 microns; lines plotted are for airmasses of 1., 2.,
and 3.

Last modified by Ka Chun Yu.