PyRTM Reference

Input Parameters[edit | edit source]

This table lists default parameters for the Python RTM wrappers v0.2. It is accurate as of September 2012, but for the best reference check the source code: https://github.com/Queens-Applied-Sustainability/PyRTM/blob/master/rtm/settings.py

You can always see your particular installation's default input parameters. They are in a dictionary called defaults in rtm.settings

phil@ubuntu:~$ python
Python 2.7.3 (default, Aug 1 2012, 05:14:39)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import rtm
>>> for setting in rtm.settings.defaults.items():

... print('{0: <26}{1}'.format(*setting))

The above code should print out a formatted table of setting defaults. The table below is most useful for checking whether a setting is supported in SBdart or SMARTS, and for the notes.

Parameter	Default	Unit	SMARTS	SBdart	Notes
description	'Default Config'		yes	yes
solar_constant	1367	W/m^2	yes	-
season	'summer'	summer or winter	yes	-	very tiny effect
time	parsedt('2012-10-11 12:00:00 -0500')		yes	yes	time zone is important! must be a python datetime object (in the default case, parsedt has already been imported from dateutil.parser import parse as parsedt
latitude	44	degrees	yes	yes	north-positive
longitude	283.7	degrees	yes	yes	east-positive!
elevation	0	metres???	yes	yes	unit should be double-checked
surface_type	'vegetation'		yes	yes	see below
single_scattering_albedo	0.8		yes	yes
atmosphere	'sub-arctic summer'		yes	yes	see below
average_daily_temperature	15	degrees C	yes	-
temperature	15	degrees C	yes	-	used in the wrapper's Relative Humidity calculation for SBdart
pressure	1013.25	mb	yes	yes
relative_humidity	35	%	yes	yes
angstroms_coefficient	0.08		yes	yes
angstroms_exponent	1.1977		yes	yes
aerosol_asymmetry	0.6		yes	yes
boundary_layer_ozone	0.3	atm-cm	yes	yes
carbon_dioxide	390	ppm	yes	yes
methane	0.2	ppm	yes	yes
carbon_monoxide	0	ppm	yes	yes
sulphur_dioxide	0.01	ppm	yes	yes
nitric_oxide	0.075	ppm	yes	yes
nitric_acid	0.001	ppm	yes	yes
nitrogen_dioxide	0.005	ppm	yes	yes
tropospheric_ozone	0.0023	yppm	yes	yes
formaldehyde	0.001	ppm	yes	-
nitrous_acid	0.0005	ppm	yes	-
nitrogen_trioxide	1e-5	ppm	yes	-
nitrogen	781000	ppm	-	yes
oxygen	209000	ppm	-	yes
nitrous_oxide	0.32	ppm	-	yes
amonia	5e-4	ppm	-	yes
cloud_altitude	2	km	-	yes	bottom of cloud layer. Cloud settings suggested by QIW. SMARTS does not support cloud cover.
cloud_thickness	1	km	-	yes
cloud_optical_depth	0		-	yes
lower_limit	0.28	um	yes	yes	Spectral limits and resolutions have restrictions; check the SMARTS and SBdart documentation.
upper_limit	2.8	um	yes	yes
resolution	0.01	um	yes	yes	Check RTM documentation. Actual computed resolution may be dependent on the spectral range of the output.

Pollution Settings[edit | edit source]

The SMARTS documentation suggests four sets of gas concentrations to approximate different levels of pollution. The default PyRTM gas settings are based on the suggested values for light pollution.

All of the suggested gas combinations are included with PyRTM for convenience. They may be accessed through a dictionary in the settings module: rtm.settings.pollution.

As above, always check the source code for the latest reference values. The following table is correct as of September 2012:

Polution Level	formaldehyde	methane	carbon_monoxide	nitrous_acid	nitric_acid	nitric_oxide	nitrogen_dioxide	nitrogen_trioxide	tropospheric_ozone	sulphur_dioxide
pristine	-0.003	0	-0.1	-9.9e-4	0	0	0	-4.5e-4	-0.007	0
light_pollution	0.001	0.2	0	0.0005	0.001	0.075	0.005	1e-5	0.023	0.01
moderate	0.007	0.3	0.35	0.002	0.005	0.2	0.02	5e-5	0.053	0.05
severe	0.01	0.4	9.9	0.012	0.5	0.2	2e-4	0.175	0.2

Pollution Settings Example[edit | edit source]

Create a SMARTS model with the moderate pollution settings:

phil@ubuntu:~$ python
Python 2.7.3 (default, Aug 1 2012, 05:14:39)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import rtm
>>> moderate_model = rtm.SMARTS(rtm.settings.pollution['moderate'])

Verify the settings have been applied:

>>> moderate_model
{'description': 'Default Config', 'nitrogen_trioxide': 5e-05, 'sulphur_dioxide': 0.05,
'nitric_acid': 0.005, 'longitude': 283.7, 'nitrogen_dioxide': 0.02, 'latitude': 44, 'f
ormaldehyde': 0.007, 'tropospheric_ozone': 0.053, 'time': datetime.datetime(2012, 10,
11, 12, 0, tzinfo=tzoffset(None, -18000)), 'nitrous_acid': 0.002, 'carbon_monoxide': 0

.35, 'nitric_oxide': 0.2, 'methane': 0.3}

Switch the model to the sever pollution settings:

>>> moderate_model.update(rtm.settings.pollution['severe'])

Verify the gasses have changed...

>>> moderate_model
{'description': 'Default Config', 'nitrogen_trioxide': 0.0002, 'nitrogen_dioxide': 0.2

, 'nitrous_acid': 0.01, 'formaldehyde': 0.01, 'sulphur_dioxide': 0.2, 'nitric_acid': 0 .012, 'longitude': 283.7, 'nitric_oxide': 0.5, 'carbon_monoxide': 9.9, 'tropospheric_o

zone': 0.175, 'time': datetime.datetime(2012, 10, 11, 12, 0, tzinfo=tzoffset(None, -18
000)), 'latitude': 44, 'methane': 0.4}

Outputs[edit | edit source]

Properties[edit | edit source]

Irradiance and Spectrum[edit | edit source]

Integrated broadband irradiance is available for all outputs on both SMARTS and SBdart via the irradiance attribute.

>>> model_instance.irradiance['global']
623.56
>>> model_instance.spectrum['direct']
array([ 2.97600000e-22, 8.31100000e-07, 2.74400000e-01,
				 1.35100000e+01, 6.62500000e+01, 1.49100000e+02,
				 1.75200000e+02, 1.95300000e+02, 2.39800000e+02])
>>>

Output Models[edit | edit source]

type	SMARTS	SBdart	notes
global	yes	yes
direct	yes	no	will be implemented soon