a piece of humble pie this map shows the state of the southern california desert about 10,000 years...
TRANSCRIPT
A piece of humble pie
This map shows the state of the southern California desert about 10,000 years ago.
The presence of these lakes is confirmed by oral histories, packrat nests, water-line marks on mountain-sides, fish traps, lakeside campsites and other evidence.
Is this much climate change really due to variations in the Earth’s orbit?
Do we really think we understand climate change?
MODELING TSIVARIATIONS USING AUTOCLASS SOFTWARE ON MWO DATA
R.K. Ulrich1 · D. Parker1 · L. Bertello1 · J. Boyden1
1 Department of Physics and Astronomy, University ofCalifornia, Los Angeles 90095 email: [email protected]: [email protected] email: [email protected]: [email protected]
How AutoClass Works
AutoClass works on a set of observations.
Each observation has attributes which are values of observed parameters.
Each observation is referred to as an instance.
In our case the instance is a single pixel.
The attributes are the absolute value of the magnetic field and a line intensity ratio Ir.
The line intensity ratio is:
Sample Images
Intensity ratioAbsolute magnetic field
How AutoClass Works (cont.) AutoClass takes all observed
instances and uses posterior Bayesian statistics to determine a set of classes to which all observations can be assigned.
The output of an AutoClass search is a number of classes.
Each class is described by probability distribution functions for the values of the attributes.
For our application we get central values and gaussian widths for Ir and |B|.
The PDF’s for an 18-class classification.AutoClass finds that 18 classes describe a set of observations consisting of 12 image pairs.
Each image pair consists of an absolute field magnetogram and in intensity ratiogram.
The image pairs were selected as one per year for the period 1996 to 2008.
Application of AutoClass to MWO Data There are J classes denoted by index
j. Each pixel i is assigned a probability
that it belongs to class j. We remember which image the
pixels come from and denote that image by index n.
The sum over all pixels on image n of the probabilities each belongs to class j gives us an index Ajn which is effectively the fractional area of solar image n covered by class j.
Properties of the Indicies The indicies obey:
The TSI is reproduced by:
The sj represent the TSI the sun would have if entirely covered by class j.
A deviation in sj is usefully defined as:
with
Properties of the classes
Modeling the TSI, part 1
Modeling the TSI part 2
Modeling the TSI part 3
Simulation of a TSI image
Comparison between an SBI image and a TSI simulation
Quiet Groups Q0 and Q1
Groups Network, Plage 0, Plage 1
Time trends of the groups
Log of the fractional areas
Final Scatter DiagramThe final cross correlation reaches 0.97. The Virgo data has been detrended for the drift from the previous time of solar minimum to the present condition.
The comparison has also been smoothed with a three-point wide Gaussian.
Points at the beginning of the series are brown while those at the end are green.