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<front>
<journal-meta>
<journal-id journal-id-type="publisher">NPG</journal-id>
<journal-title-group>
<journal-title>Nonlinear Processes in Geophysics</journal-title>
<abbrev-journal-title abbrev-type="publisher">NPG</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Nonlin. Processes Geophys.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1607-7946</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/npg-21-1145-2014</article-id>
<title-group>
<article-title>Non-parametric Bayesian mixture of sparse regressions with application towards feature selection for statistical downscaling</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Das</surname>
<given-names>D.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Dy</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ross</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Obradovic</surname>
<given-names>Z.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ganguly</surname>
<given-names>A. R.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Sustainability and Data Sciences Lab, Northeastern University, Boston, MA, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Center for Data Analytics and Biomedical Informatics, Temple University, Philadelphia, PA, USA</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>01</day>
<month>12</month>
<year>2014</year>
</pub-date>
<volume>21</volume>
<issue>6</issue>
<fpage>1145</fpage>
<lpage>1157</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2014 D. Das et al.</copyright-statement>
<copyright-year>2014</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://npg.copernicus.org/articles/21/1145/2014/npg-21-1145-2014.html">This article is available from https://npg.copernicus.org/articles/21/1145/2014/npg-21-1145-2014.html</self-uri>
<self-uri xlink:href="https://npg.copernicus.org/articles/21/1145/2014/npg-21-1145-2014.pdf">The full text article is available as a PDF file from https://npg.copernicus.org/articles/21/1145/2014/npg-21-1145-2014.pdf</self-uri>
<abstract>
<p>Climate projections simulated by Global Climate Models (GCMs) are often used
for assessing the impacts of climate change. However, the relatively coarse
resolutions of GCM outputs often preclude their application to
accurately assessing the effects of climate change on finer regional-scale
phenomena. Downscaling of climate variables from coarser to finer regional
scales using statistical methods is often performed for regional climate
projections. Statistical downscaling (SD) is based on the understanding that
the regional climate is influenced by two factors – the large-scale climatic
state and the regional or local features. A transfer function approach of SD
involves learning a regression model that relates these features
(predictors) to a climatic variable of interest (predictand) based on the
past observations. However, often a single regression model is not sufficient
to describe complex dynamic relationships between the predictors and
predictand. We focus on the covariate selection part of the transfer function
approach and propose a nonparametric Bayesian mixture of sparse regression
models based on Dirichlet process (DP) for simultaneous clustering and
discovery of covariates within the clusters while automatically finding the
number of clusters. Sparse linear models are parsimonious and hence
more generalizable than non-sparse alternatives, and lend themselves to
domain relevant interpretation. Applications to synthetic data demonstrate
the value of the new approach and preliminary results related to feature
selection for statistical downscaling show that our method can lead to new insights.</p>
</abstract>
<counts><page-count count="13"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Science Foundation</funding-source>
<award-id>1029711</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple">Antoniak, C.: Mixtures of Dirichlet processes with applications to Bayesian nonparametric problems, Ann. Stat., 2, 1152–1174, 1974.</mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple">Bader, D. C., Covey, C., Gutkowski Jr., W. J., Held, I. M., Kunkel, K. E., Miller, R. L., Tokmakian, R. T., and Zhang, M. H.: Climate Models: An Assessment of Strengths and Limitations, US Climate Change Science Program Synthesis and Assessment Product 3.1, Department of Energy, Office of Biological and Environmental Research, 124 pp., available at: &lt;a href=&quot;http://pubs.giss.nasa.gov/docs/2008/2008_Bader_etal_1.pdf&quot;&gt;http://pubs.giss.nasa.gov/docs/2008/2008_Bader_etal_1.pdf&lt;/a&gt; (last access: 20 July 2014), 2008.</mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple">Basu, S., Bilenko, M., Banerjee, A., and Mooney, R.: Probabilistic semi-supervised clustering with constraints, J. Mach. Learn. Res., 71–98, 2006.</mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple">Benestad, R., Hanssen-Bauer, I., and Chen, D.: Empirical-Statistical Downscaling, World Scientific Publishing Company, New Jersey, London, 2008.</mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple">Bishop, C. and Svenskn, M.: Bayesian hierarchical mixtures of experts, in: Uncertainty in Artificial Intelligence, Morgan Kaufman, San Francisco, CA, 57–64, 2002.</mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple">Blei, D. M. and Jordan, M. I.: Variational inference for Dirichlet process mixtures, Bayesian Anal., 1, 121–143, 2006.</mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple">Easterling, D. R., Karl, T. R., Mason, E. H., Hughes, P. Y., and Bowman, D. P.: United States Historical Climatology Network (USHCN) Monthly Temperature and Precipitation Data, Tech. rep., Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee, available at: &lt;a href=&quot;http://cdiac.ornl.gov/epubs/ndp/ushcn/ushcn.html&quot;&gt;http://cdiac.ornl.gov/epubs/ndp/ushcn/ushcn.html&lt;/a&gt; (last access: 2 April 2014), 1996.</mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple">Ebtehaj, A. M., Foufoula-Georgiou, E., and Lerman, G.: Sparse regularization for precipitation downscaling, J. Geophys. Res., 117, 1–12, &lt;a href=&quot;http://dx.doi.org/10.1029/2011JD017057&quot;&gt;https://doi.org/10.1029/2011JD017057&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple">Ferguson, T.: A Bayesian analysis of some nonparametric problems, Ann. Stat., 1, 209–230, 1973.</mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple">Geman, S. and Geman, D.: Stochastic relaxation, Gibbs distributions, and the Bayesian restoration of images, IEEE T. Pattern Anal., PAMI-6, 721–741, 1984.</mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple">Ghosh, S.: SVM-PGSL coupled approach for statistical downscaling to predict rainfall from GCM output, J. Geophys. Res., 115, D22102, &lt;a href=&quot;http://dx.doi.org/10.1029/2009JD013548&quot;&gt;https://doi.org/10.1029/2009JD013548&lt;/a&gt;, 2010.</mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple">Greene, A. M., Robertson, A. W., Smyth, P., and Triglia, S.: Downscaling projections of Indian monsoon rainfall using a nonhomogeneous hidden Markov model, Q. J. Roy. Meteorol. Soc., 137, 347–359, 2011.</mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple">Hespanha, J. P.: An efficient MATLAB Algorithm for Graph Partitioning, Tech. rep., University of California, Santa Barbara, available at: &lt;a href=&quot;http://www.ece.ucsb.edu/ hespanha/techrep.html&quot;&gt;http://www.ece.ucsb.edu/ hespanha/techrep.html&lt;/a&gt; (last access: 2 April 2014), 2004.</mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple">Ishwaran, H. and James, L. F.: Gibbs sampling methods for stick-breaking priors, J. Am. Stat. Assoc., 96, 161–173, 2001.</mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple">Kannan, S. and Ghosh, S.: Prediction of daily rainfall state in a river basin using statistical downscaling from GCM output, Stoch. Env. Res. Risk. A., 25, 457–474, &lt;a href=&quot;http://dx.doi.org/10.1007/s00477-010-0415-y&quot;&gt;https://doi.org/10.1007/s00477-010-0415-y&lt;/a&gt;, 2010.</mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple">Kedem, B. and Chiu, L. S.: On the lognormality of rain rate, P. Natl. Acad. Sci. USA, 84, 901–905, 1987.</mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple">Knutti, R. and Sedláček, J.: Robustness and uncertainties in the new CMIP5 climate model projections, Nat. Clim. Change, 3, 369–373, &lt;a href=&quot;http://dx.doi.org/10.1038/nclimate1716&quot;&gt;https://doi.org/10.1038/nclimate1716&lt;/a&gt;, 2013.</mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple">Kumar, D., Kodra, E., and Ganguly, A. R.: Regional and seasonal intercomparison of CMIP3 and CMIP5 climate model ensembles for temperature and precipitation, Clim. Dynam., 43, 2491–2518, &lt;a href=&quot;http://dx.doi.org/10.1007/s00382-014-2070-3&quot;&gt;https://doi.org/10.1007/s00382-014-2070-3&lt;/a&gt;, 2014.</mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple">Mesinger, F., DiMego, G., Kalnay, E., Mitchell, K., Shafran, P. C., Ebisuzaki, W., Jović, D., Woollen, J., Rogers, E., Berbery, E. H., Ek, M. B., Fan, Y., Grumbine, R., Higgins, W., Li, H., Lin, Y., Manikin, G., Parrish, D., and Shi, W.: North American regional reanalysis, B. Am. Meteorol. Soc., 87, 343–360, &lt;a href=&quot;http://dx.doi.org/10.1175/BAMS-87-3-343&quot;&gt;https://doi.org/10.1175/BAMS-87-3-343&lt;/a&gt;, 2006.</mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple">NOAA: Climate Indices: Monthly Atmospheric and Ocean Time Series, available at: &lt;a href=&quot;http://www.esrl.noaa.gov/psd/data/climateindices/list/&quot;&gt;http://www.esrl.noaa.gov/psd/data/climateindices/list/&lt;/a&gt;, last access: 2 April 2014.</mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple">Park, T. and Casella, G.: The Bayesian LASSO, J. Am. Stat. Assoc., 103, 681–686, &lt;a href=&quot;http://dx.doi.org/10.1198/016214508000000337&quot;&gt;https://doi.org/10.1198/016214508000000337&lt;/a&gt;, 2008.</mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple">Phatak, A., Bates, B., and Charles, S.: Statistical downscaling of rainfall data using sparse variable selection methods, Environ. Modell. Softw., 26, 1363–1371, &lt;a href=&quot;http://dx.doi.org/10.1016/j.envsoft.2011.05.007&quot;&gt;https://doi.org/10.1016/j.envsoft.2011.05.007&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple">Ross, J. and Dy, J.: Nonparametric Mixture of Gaussian Processes with Constraints, The 30th International Conference of Machine Learning, Atlanta, GA, 2013.</mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple">Sethuraman, J.: A constructive definition of Dirichlet priors, Stat. Sinica, 4, 639–650, 1994.</mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple">Tarjan, R.: Depth-first search and linear graph algorithms, SIAM J. Comput., 1, 146–160, 1972.</mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple">Tibshirani, R.: Regression shrinkage and selection via the LASSO, J. Roy. Stat. Soc. B, 58, 267–288, 1994.</mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple">Wilby, R., Charles, S., Zorita, E., and Timbal, B.: Guidelines for use of climate scenarios developed from statistical downscaling methods, Tech. Rep. August, Inter-Governmental Panel for Climate Change, available at: &lt;a href=&quot;http://www.narccap.ucar.edu/doc/tgica-guidance-2004.pdf&quot;&gt;http://www.narccap.ucar.edu/doc/tgica-guidance-2004.pdf&lt;/a&gt; (last access: 2 April 2014), 2004.</mixed-citation>
</ref>
</ref-list>
</back>
</article>