<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">AMT</journal-id>
<journal-title-group>
<journal-title>Atmospheric Measurement Techniques</journal-title>
<abbrev-journal-title abbrev-type="publisher">AMT</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Atmos. Meas. Tech.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1867-8548</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/amt-8-3685-2015</article-id>
<title-group>
<article-title>Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Chandra</surname>
<given-names>A.</given-names>
<ext-link>https://orcid.org/0000-0002-8818-171X</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>C.</given-names>
<ext-link>https://orcid.org/0000-0001-9708-1561</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kollias</surname>
<given-names>P.</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>Matrosov</surname>
<given-names>S.</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>Szyrmer</surname>
<given-names>W.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, Florida, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Canada</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Cooperative Institute for Research in Environmental   Sciences, University of Colorado and NOAA/Earth System Research   Laboratory, Boulder, Colorado, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>14</day>
<month>09</month>
<year>2015</year>
</pub-date>
<volume>8</volume>
<issue>9</issue>
<fpage>3685</fpage>
<lpage>3699</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2015 A. Chandra et al.</copyright-statement>
<copyright-year>2015</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://amt.copernicus.org/articles/8/3685/2015/amt-8-3685-2015.html">This article is available from https://amt.copernicus.org/articles/8/3685/2015/amt-8-3685-2015.html</self-uri>
<self-uri xlink:href="https://amt.copernicus.org/articles/8/3685/2015/amt-8-3685-2015.pdf">The full text article is available as a PDF file from https://amt.copernicus.org/articles/8/3685/2015/amt-8-3685-2015.pdf</self-uri>
<abstract>
<p>The use of millimeter wavelength radars for probing precipitation has
recently gained interest. However, estimation of precipitation variables is
not straightforward due to strong signal attenuation, radar receiver
saturation, antenna wet radome effects and natural microphysical variability.
Here, an automated algorithm is developed for routinely retrieving rain rates
from the profiling Ka-band (35-GHz) ARM (Atmospheric Radiation
Measurement) zenith radars (KAZR). A 1-dimensional, simple, steady state
microphysical model is used to estimate impacts of microphysical processes
and attenuation on the profiles of radar observables at 35-GHz and thus
provide criteria for identifying situations when attenuation or microphysical
processes dominate KAZR observations. KAZR observations are also screened for
signal saturation and wet radome effects. The algorithm is implemented in two
steps: high rain rates are retrieved by using the amount of attenuation in
rain layers, while low rain rates are retrieved from the reflectivity–rain
rate (&lt;i&gt;Z&lt;/i&gt;&lt;sub&gt;&lt;i&gt;e&lt;/i&gt;&lt;/sub&gt;–&lt;i&gt;R&lt;/i&gt;) relation. Observations collected by the KAZR, rain gauge,
disdrometer and scanning precipitating radars during the DYNAMO/AMIE field
campaign at the Gan Island of the tropical Indian Ocean are used to validate
the proposed approach. The differences in the rain accumulation from the
proposed algorithm are quantified. The results indicate that the proposed
algorithm has a potential for deriving continuous rain rate statistics in the
tropics.</p>
</abstract>
<counts><page-count count="15"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple">Aydin, K. and Daisley, S. E. A.: Relationships between rainfall rate and 35 GHz attenuation and differential attenuation: modeling the effects of raindrop size distribution, canting, and oscillation, IEEE T. Geosci. Remote, 40, 2343–2351, 2002.</mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple">Bohren, C. F. and Huffman, D. R.: Absorption and Scattering of Light by Small Particles, Wiley, New York, USA, 530 pp., 1983.</mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple">Feng, Z., McFarlane, S. A., Schumacher, C., Ellis, S., and Bharadwaj, N.: Constructing a merged cloud-precipitation radar dataset for tropical convective clouds during the DY- NAMO/AMIE Experiment at Addu Atoll, J. Atmos. Ocean. Technol., 31, 1021–1042, &lt;a href=&quot;http://dx.doi.org/10.1175/JTECH-D-13-00132.1&quot;&gt;https://doi.org/10.1175/JTECH-D-13-00132.1&lt;/a&gt;, 2014.</mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple">Geerts, B. and Dawei, Y.: Classification and characterization of tropical precipitation based on high-resolution airborne vertical incidence radar, Part I: Classification, J. Appl. Meteorol., 43, 1554–1566, 2004.</mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple">Huffman, G. J., Bolvin, D. T., Nelkin, E. J., Wolff, D. B., Adler, R. F., Gu, G., Hong, Y., Bowman, K. P., and Stocker, E. F.: The TRMM Multisatellite Precipitation Analysis (TMPA): quasi-global, multiyear, combined-sensor precipitation estimates at fine scales, J. Hydrometeorol., 8, 38–55, 2007.</mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple">Illingworth, A. J. and Blackman, T. M.: The need to represent raindrop size spectra as normalized gamma distributions for the interpretation of polarization radar observations, J. Appl. Meteorol., 41, 286–297, 2002.</mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple">Kollias, P., Clothiaux, E. E., Miller, M. A., Albrecht, B. A., Stephens, G. L., and Ackerman, T. P.: Millimeter-wavelength radars: new frontier in atmospheric cloud and precipitation research, B. Am. Meteorol. Soc., 88, 1608–1624, &lt;a href=&quot;http://dx.doi.org/10.1175/BAMS-88-10-1608&quot;&gt;https://doi.org/10.1175/BAMS-88-10-1608&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple">Kollias, P., Szyrmer, W., Remillard, J., and Luke, E.: Cloud radar Doppler spectra in drizzling stratiform clouds, Part II: Observations and microphysical modeling of drizzle evolution, J. Geophys. Res.-Atmos., 116, D13203, &lt;a href=&quot;http://dx.doi.org/10.1029/2010JD015238&quot;&gt;https://doi.org/10.1029/2010JD015238&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple">Kruger, A., and Krajewski, W.: Two-dimensional video disdrometer: A description, J. Atmos. Oceanic Technol., 19, 602–617, &lt;a href=&quot;http://dx.doi.org/10.1175/1520-0426(2002)019&lt;0602:TDVDAD&gt;2.0.CO;2&quot;&gt;https://doi.org/10.1175/1520-0426(2002)019&lt;0602:TDVDAD&gt;2.0.CO;2&lt;/a&gt;, 2002.</mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple">Kummerow, C., Barnes, W., Kozu, T., Shiue, J., and Simpson, J.: The Tropical Rainfall Measuring Mission (TRMM) sensor package, J. Atmos. Ocean Tech., 15, 809–817, 1998.</mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple">Lhermitte, R.: Attenuation and scattering of millimeter wavelength radiation by cloud and precipitation, J. Atmos. Ocean Tech., 7, 464–479, 1990.</mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple">Lebsock, M. D. and L&apos;Ecuyer, T. S.: The retrieval of warm rain from CloudSat, J. Geophys. Res., 116, D20209, &lt;a href=&quot;http://dx.doi.org/10.1029/2011JD016076&quot;&gt;https://doi.org/10.1029/2011JD016076&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple">Liebe, H. J., Huffort, G. A., and Manage, T.: A model for the complex permittivity of water at frequencies below 1 THz, Int. J. Infrared. Milli., 12, 659–675, 1991.</mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple">Marshall, J. S. and Palmer, W. Mc K.: The distribution of raindrops with size, J. Meteor., 5, 165–166, 1948.</mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple">Mather, J. H. and Voyles, J. W.: The ARM Climate Research Facility: a review of structure and capabilities, B. Am. Meteorol. Soc., 94, 377–392, &lt;a href=&quot;http://dx.doi.org/10.1175/BAMS-D-11-00218.1&quot;&gt;https://doi.org/10.1175/BAMS-D-11-00218.1&lt;/a&gt;, 2013.</mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple">Martner, B. E., Yuter, S. E., White, A. B., Matrosov, S. Y., Kingsmill, D. E., and Ralph, F. M.: Raindrop size distributions and rain characteristics in California-coastal rainfall for periods with and without a radar bright band, J. Hydrometeor., 9, 408–425, 2008.</mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple">Matrosov, S. Y.: Attenuation-based estimates of rainfall rates aloft with vertically pointing Ka-band radars, J. Atmos. Ocean Tech., 22, 43–54, 2005.</mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple">Matrosov, S. Y.: Potential for attenuation-based estimations of rainfall rate from CloudSat, Geophys. Res. Lett., 34, L05817, &lt;a href=&quot;http://dx.doi.org/10.1029/2006GL029161&quot;&gt;https://doi.org/10.1029/2006GL029161&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple">Matrosov, S. Y.: Synergetic use of millimeter- and centimeter-wavelength radars for retrievals of cloud and rainfall parameters, Atmos. Chem. Phys., 10, 3321–3331, &lt;a href=&quot;http://dx.doi.org/10.5194/acp-10-3321-2010&quot;&gt;https://doi.org/10.5194/acp-10-3321-2010&lt;/a&gt;, 2010.</mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple">Matrosov, S. Y., Uttal, T., and Hazen, D. A.: Evaluation of Radar Reflectivity-Based Estimates of Water Content in Stratiform Marine Clouds, J. Appl. Meteor., 43, 405–419, 2004.</mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple">Matrosov, S. Y., May, P. T., and Shupe, M. D.: Rainfall profiling using Atmospheric Measurement Program vertically pointing 8 mm wavelength radars, J. Atmos. Ocean Tech., 23, 1478–1491, 2006.</mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple">Mittermaier, M. P., Hogan, R. J., and Illingworth, A. J.: Using mesoscale winds for correcting wind-drift errors in radar estimates of surface rainfall, Q. J. Roy. Meteor. Soc., 130, 2105–2123, 2004.</mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple">Rajopadhyaya, D. K., May, P. T., Cifelli, R., Avery, S. K., Williams, C. R., Ecklund, W. L., and Gage, K. S.: The effect of vertical air motions on rain rates and median volume diameter determined from combined UHF and VHF wind profiler measurements and comparisons with rain gauge measurements, J. Atmos. Oceanic Technol., 15, 1306–1319, 1998.</mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple">Ryzhkov, A. V. and Zrnic, D. S.: Assessment of rainfall measurement that uses specific differential phase, J. Appl. Meteor., 35, 2080–2090, 1996.</mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple">Sachidananda, M. and Zrnic, D. S.: Rain rate estimated from differential polarization measurements, J. Atmos. Oceanic Technol., 4, 588–598, 1987.</mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple">Short, D. A., Thiele, O. W., and McPhaden, M. J.: Optical Rain gauge performance: Second workshop on Optical Rain Gauge Measurements, NASA Technical report, Washington, USA, NASA-CP-3288, 1994.</mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple">Tokay, A., Hartmann, P., Battaglia, A., Gage, K. S., Clark, W. L., and Williams, C. R.: A field study of reflectivity and &lt;i&gt;Z&lt;/i&gt;−&lt;i&gt;R&lt;/i&gt; relations using vertically pointing radars and disdrometers, J. Atmos. Ocean Tech., 26, 1120–1134, 2009.</mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple">Wakasugi, K., Mizutani, A., Matsuo, M., Fukao, A., and Kato, S.: A direct method for deriving drop-size distribution and vertical air velocities from VHF Doppler radar spectra, J. Atmos. Oceanic Technol., 3, 623–629, 1986.</mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple">Wang, J.-J., Alder, R. F., Huffman, G. J., and Bolvin, D.: An updated TRMM composite climatology of tropical rainfall and its validation, J. Climate, 27, 273–284, &lt;a href=&quot;http://dx.doi.org/10.1175/JCLI-D-13-00331.1&quot;&gt;https://doi.org/10.1175/JCLI-D-13-00331.1&lt;/a&gt;, 2013.</mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple">Yoneyama, K., Zhang, C., and Long, C. N.: Tracking pulses of the Madden–Julian Oscillation, B. Am. Meteorol. Soc., 94, 1871–1891, 2013.</mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple">Zhang, C.: Madden–Julian Oscillation: bridging weather and climate, B. Am. Meteorol. Soc., 94, 1849–1870, &lt;a href=&quot;http://dx.doi.org/10.1175/BAMS-D-12-00026.1&quot;&gt;https://doi.org/10.1175/BAMS-D-12-00026.1&lt;/a&gt;, 2013.</mixed-citation>
</ref>
</ref-list>
</back>
</article>