Retrieving Properties of Thin Clouds from Solar Aureole Measurements
This paper describes a newly designed Sun and Aureole Measurement (SAM) aureolegraph and the first results obtained with this instrument. SAM measurements of solar aureoles produced by cirrus and cumulus clouds were taken at the Atmospheric Radiation Measurement Program (ARM) Central Facility in Okl...
| Main Authors: | , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Meteorological Society
2010
|
| Online Access: | http://hdl.handle.net/1721.1/57579 https://orcid.org/0000-0003-3182-5569 |
| _version_ | 1826200635994800128 |
|---|---|
| author | Joss, Paul C. DeVore, J. G. Stair, A. T. LePage, A. Rall, D. Atkinson, J. Villanucci, D. McClatchey, R. A. Rappaport, Saul A |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Joss, Paul C. DeVore, J. G. Stair, A. T. LePage, A. Rall, D. Atkinson, J. Villanucci, D. McClatchey, R. A. Rappaport, Saul A |
| author_sort | Joss, Paul C. |
| collection | MIT |
| description | This paper describes a newly designed Sun and Aureole Measurement (SAM) aureolegraph and the first results obtained with this instrument. SAM measurements of solar aureoles produced by cirrus and cumulus clouds were taken at the Atmospheric Radiation Measurement Program (ARM) Central Facility in Oklahoma during field experiments conducted in June 2007 and compared with simultaneous measurements from a variety of other ground-based instruments. A theoretical relationship between the slope of the aureole profile and the size distribution of spherical cloud particles is based on approximating scattering as due solely to diffraction, which in turn is approximated using a rectangle function. When the particle size distribution is expressed as a power-law function of radius, the aureole radiance as a function of angle from the center of the solar disk also follows a power law, with the sum of the two powers being −5. This result also holds if diffraction is modeled with an Airy function. The diffraction approximation is applied to SAM measurements with optical depths 2 to derive the effective radii of cloud particles and particle size distributions between 2.5 and 25 μm. The SAM results yielded information on cloud properties complementary to that obtained with ARM Central Facility instrumentation. A network of automated SAM units [similar to the Aerosol Robotic Network (AERONET) system] would provide a practical means to gain fundamental new information on the global statistical properties of thin (optical depth 10) clouds, thereby providing unique information on the effects of such clouds upon the earth’s energy budget. |
| first_indexed | 2024-09-23T11:39:30Z |
| format | Article |
| id | mit-1721.1/57579 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:39:30Z |
| publishDate | 2010 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/575792022-10-01T05:05:06Z Retrieving Properties of Thin Clouds from Solar Aureole Measurements Joss, Paul C. DeVore, J. G. Stair, A. T. LePage, A. Rall, D. Atkinson, J. Villanucci, D. McClatchey, R. A. Rappaport, Saul A Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Joss, Paul C. Joss, Paul C. Rappaport, Saul A. This paper describes a newly designed Sun and Aureole Measurement (SAM) aureolegraph and the first results obtained with this instrument. SAM measurements of solar aureoles produced by cirrus and cumulus clouds were taken at the Atmospheric Radiation Measurement Program (ARM) Central Facility in Oklahoma during field experiments conducted in June 2007 and compared with simultaneous measurements from a variety of other ground-based instruments. A theoretical relationship between the slope of the aureole profile and the size distribution of spherical cloud particles is based on approximating scattering as due solely to diffraction, which in turn is approximated using a rectangle function. When the particle size distribution is expressed as a power-law function of radius, the aureole radiance as a function of angle from the center of the solar disk also follows a power law, with the sum of the two powers being −5. This result also holds if diffraction is modeled with an Airy function. The diffraction approximation is applied to SAM measurements with optical depths 2 to derive the effective radii of cloud particles and particle size distributions between 2.5 and 25 μm. The SAM results yielded information on cloud properties complementary to that obtained with ARM Central Facility instrumentation. A network of automated SAM units [similar to the Aerosol Robotic Network (AERONET) system] would provide a practical means to gain fundamental new information on the global statistical properties of thin (optical depth 10) clouds, thereby providing unique information on the effects of such clouds upon the earth’s energy budget. United States Department of Energy National Aeronautics and Space Administration 2010-08-27T14:05:19Z 2010-08-27T14:05:19Z 2009-06 2009-02 Article http://purl.org/eprint/type/JournalArticle 0739-0572 1520-0426 http://hdl.handle.net/1721.1/57579 DeVore, J. G et al. “Retrieving Properties of Thin Clouds from Solar Aureole Measurements.” Journal of Atmospheric and Oceanic Technology 26.12 (2009): 2531-2548. © 2009 American Meteorological Society. https://orcid.org/0000-0003-3182-5569 en_US http://dx.doi.org/10.1175/2009jtecha1289.1 Journal of Atmospheric and Oceanic Technology Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Joss, Paul C. DeVore, J. G. Stair, A. T. LePage, A. Rall, D. Atkinson, J. Villanucci, D. McClatchey, R. A. Rappaport, Saul A Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title | Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title_full | Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title_fullStr | Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title_full_unstemmed | Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title_short | Retrieving Properties of Thin Clouds from Solar Aureole Measurements |
| title_sort | retrieving properties of thin clouds from solar aureole measurements |
| url | http://hdl.handle.net/1721.1/57579 https://orcid.org/0000-0003-3182-5569 |
| work_keys_str_mv | AT josspaulc retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT devorejg retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT stairat retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT lepagea retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT ralld retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT atkinsonj retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT villanuccid retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT mcclatcheyra retrievingpropertiesofthincloudsfromsolaraureolemeasurements AT rappaportsaula retrievingpropertiesofthincloudsfromsolaraureolemeasurements |