Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model
<p>As a long-standing problem in climate models, large positive shortwave radiation biases exist at the surface over the Southern Ocean, impacting the accurate simulation of sea surface temperature, atmospheric circulation, and precipitation. Underestimations of low-level cloud fraction and li...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/14691/2023/acp-23-14691-2023.pdf |
| _version_ | 1797447645627678720 |
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| author | Z. Pei Z. Pei Z. Pei S. L. Fiddes S. L. Fiddes W. J. R. French W. J. R. French S. P. Alexander S. P. Alexander M. D. Mallet P. Kuma A. McDonald |
| author_facet | Z. Pei Z. Pei Z. Pei S. L. Fiddes S. L. Fiddes W. J. R. French W. J. R. French S. P. Alexander S. P. Alexander M. D. Mallet P. Kuma A. McDonald |
| author_sort | Z. Pei |
| collection | DOAJ |
| description | <p>As a long-standing problem in climate models, large positive shortwave radiation biases exist at the surface over the Southern Ocean, impacting the accurate simulation of sea surface temperature, atmospheric circulation, and precipitation. Underestimations of low-level cloud fraction and liquid water content are suggested to predominantly contribute to these radiation biases. Most model evaluations for radiation focus on summer and rely on satellite products, which have their own limitations. In this work, we use surface-based observations at Macquarie Island to provide the first long-term, seasonal evaluation of both downwelling surface shortwave and longwave radiation in the Australian Community Climate and Earth System Simulator Atmosphere-only Model version 2 (ACCESS-AM2) over the Southern Ocean. The capacity of the Clouds and the Earth’s Radiant Energy System (CERES) product to simulate radiation is also investigated. We utilize the novel lidar simulator, the Automatic Lidar and Ceilometer Framework (ALCF), and all-sky cloud camera observations of cloud fraction to investigate how radiation biases are influenced by cloud properties.</p>
<p>Overall, we find an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">9.5</mn><mo>±</mo><mn mathvariant="normal">33.5</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="0adb11167a4b4eb853fdfbc6c50f311f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00001.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00001.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for downwelling surface shortwave radiation fluxes and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">2.3</mn><mo>±</mo><mn mathvariant="normal">13.5</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="c8eb1663afd2ed22a36e2c02777e79ec"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00002.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00002.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for downwelling surface longwave radiation in ACCESS-AM2 in all-sky conditions, with more pronounced shortwave biases of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">25.0</mn><mo>±</mo><mn mathvariant="normal">48.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="af5e72a62d8242938d8f650effb70f04"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00003.svg" width="64pt" height="10pt" src="acp-23-14691-2023-ie00003.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> occurring in summer. CERES presents an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">8.0</mn><mo>±</mo><mn mathvariant="normal">18.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6f8a7dc59f5c41704d433611548c4776"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00004.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00004.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for the shortwave and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">12.1</mn><mo>±</mo><mn mathvariant="normal">12.2</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="db668a2a9c0fe0a0544f1bde76ea0074"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00005.svg" width="64pt" height="10pt" src="acp-23-14691-2023-ie00005.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for the longwave in all-sky conditions. For the cloud radiative effect (CRE) biases, there is an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">4.8</mn><mo>±</mo><mn mathvariant="normal">28.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="2c7f233fbdb3c0ad3f404a8b295cb1cc"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00006.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00006.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> in ACCESS-AM2 and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">7.9</mn><mo>±</mo><mn mathvariant="normal">20.9</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="1b3293e0b6ceb452219887429640edfe"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00007.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00007.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> in CERES. An overestimation of downwelling surface shortwave radiation is associated with an underestimated cloud fraction and low-level cloud occurrence. We suggest that modeled cloud phase is also having an impact on the radiation biases. Our results show that the ACCESS-AM2 model and CERES product require further development to reduce these radiation biases not just in shortwave and in all-sky conditions, but also in longwave and in clear-sky conditions.</p> |
| first_indexed | 2024-03-09T13:58:54Z |
| format | Article |
| id | doaj.art-552106f5f4934e39b87781c7adb0b193 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-03-09T13:58:54Z |
| publishDate | 2023-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-552106f5f4934e39b87781c7adb0b1932023-11-30T11:03:11ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242023-11-0123146911471410.5194/acp-23-14691-2023Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 modelZ. Pei0Z. Pei1Z. Pei2S. L. Fiddes3S. L. Fiddes4W. J. R. French5W. J. R. French6S. P. Alexander7S. P. Alexander8M. D. Mallet9P. Kuma10A. McDonald11Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, AustraliaAustralian Research Council Centre of Excellence for Climate Extremes, University of Tasmania, Hobart, AustraliaCollege of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, ChinaAustralian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, AustraliaAustralian Research Council Centre of Excellence for Climate Extremes, University of Tasmania, Hobart, AustraliaAustralian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, AustraliaAustralian Antarctic Division, Kingston TAS, AustraliaAustralian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, AustraliaAustralian Antarctic Division, Kingston TAS, AustraliaAustralian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, AustraliaDepartment of Meteorology, Stockholm University, Stockholm, SwedenSchool of Physical and Chemical Sciences, University of Canterbury, Christchurch, Aotearoa / New Zealand<p>As a long-standing problem in climate models, large positive shortwave radiation biases exist at the surface over the Southern Ocean, impacting the accurate simulation of sea surface temperature, atmospheric circulation, and precipitation. Underestimations of low-level cloud fraction and liquid water content are suggested to predominantly contribute to these radiation biases. Most model evaluations for radiation focus on summer and rely on satellite products, which have their own limitations. In this work, we use surface-based observations at Macquarie Island to provide the first long-term, seasonal evaluation of both downwelling surface shortwave and longwave radiation in the Australian Community Climate and Earth System Simulator Atmosphere-only Model version 2 (ACCESS-AM2) over the Southern Ocean. The capacity of the Clouds and the Earth’s Radiant Energy System (CERES) product to simulate radiation is also investigated. We utilize the novel lidar simulator, the Automatic Lidar and Ceilometer Framework (ALCF), and all-sky cloud camera observations of cloud fraction to investigate how radiation biases are influenced by cloud properties.</p> <p>Overall, we find an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">9.5</mn><mo>±</mo><mn mathvariant="normal">33.5</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="0adb11167a4b4eb853fdfbc6c50f311f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00001.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00001.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for downwelling surface shortwave radiation fluxes and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">2.3</mn><mo>±</mo><mn mathvariant="normal">13.5</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="c8eb1663afd2ed22a36e2c02777e79ec"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00002.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00002.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for downwelling surface longwave radiation in ACCESS-AM2 in all-sky conditions, with more pronounced shortwave biases of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">25.0</mn><mo>±</mo><mn mathvariant="normal">48.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="af5e72a62d8242938d8f650effb70f04"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00003.svg" width="64pt" height="10pt" src="acp-23-14691-2023-ie00003.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> occurring in summer. CERES presents an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">8.0</mn><mo>±</mo><mn mathvariant="normal">18.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6f8a7dc59f5c41704d433611548c4776"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00004.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00004.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for the shortwave and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">12.1</mn><mo>±</mo><mn mathvariant="normal">12.2</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="db668a2a9c0fe0a0544f1bde76ea0074"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00005.svg" width="64pt" height="10pt" src="acp-23-14691-2023-ie00005.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> for the longwave in all-sky conditions. For the cloud radiative effect (CRE) biases, there is an overestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>+</mo><mn mathvariant="normal">4.8</mn><mo>±</mo><mn mathvariant="normal">28.0</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="2c7f233fbdb3c0ad3f404a8b295cb1cc"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00006.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00006.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> in ACCESS-AM2 and an underestimation of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">7.9</mn><mo>±</mo><mn mathvariant="normal">20.9</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="1b3293e0b6ceb452219887429640edfe"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-23-14691-2023-ie00007.svg" width="58pt" height="10pt" src="acp-23-14691-2023-ie00007.png"/></svg:svg></span></span> W m<span class="inline-formula"><sup>−2</sup></span> in CERES. An overestimation of downwelling surface shortwave radiation is associated with an underestimated cloud fraction and low-level cloud occurrence. We suggest that modeled cloud phase is also having an impact on the radiation biases. Our results show that the ACCESS-AM2 model and CERES product require further development to reduce these radiation biases not just in shortwave and in all-sky conditions, but also in longwave and in clear-sky conditions.</p>https://acp.copernicus.org/articles/23/14691/2023/acp-23-14691-2023.pdf |
| spellingShingle | Z. Pei Z. Pei Z. Pei S. L. Fiddes S. L. Fiddes W. J. R. French W. J. R. French S. P. Alexander S. P. Alexander M. D. Mallet P. Kuma A. McDonald Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model Atmospheric Chemistry and Physics |
| title | Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model |
| title_full | Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model |
| title_fullStr | Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model |
| title_full_unstemmed | Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model |
| title_short | Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model |
| title_sort | assessing the cloud radiative bias at macquarie island in the access am2 model |
| url | https://acp.copernicus.org/articles/23/14691/2023/acp-23-14691-2023.pdf |
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