solar radiation ocean
53514555
Large contribution of supercooled liquid clouds to the solar radiation budget of the Southern Ocean
The Southern Ocean is a critical region for global climate, yet large cloud and solar radiation biases over the Southern Ocean are a long standing problem in climate models and are poorly understood, leading to biases in simulated sea surface temperatures. This study shows that supercooled liquid clouds are central to understanding and simulating the Southern Ocean environment. A combination of satellite observational data and detailed radiative transfer calculations is used to quantify the impact of cloud phase and cloud vertical structure on the reflected solar radiation in the Southern Hemisphere summer. It is found that clouds with supercooled liquid tops dominate the population of liquid clouds. The observations show that clouds with supercooled liquid tops contribute between 27% and 38% to the total reflected solar radiation between 40deg and 70degS, and climate models are found to poorly simulate these clouds. The results quantify the importance of supercooled liquid clouds in the Southern Ocean environment and highlight the need to improve understanding of the physical processes that control these clouds in order to improve their simulation in numerical models. This is not only important for improving the simulation of present day climate and climate variability, but also relevant for increasing confidence in climate feedback processes and future climate projections.
Alejandro Bodas-Salcedo Peter G Hill Kalli Furtado Paul R Field James Manners Patrick Hyder
54986579
High levels of solar radiation offset impacts of ocean acidification on calcifying and non calcifying strains of Emiliania huxleyi
Coccolithophores, a globally distributed group of marine phytoplankton, showed diverse responses to ocean acidification (OA) and to combinations of OA with other environmental factors. While their growth can be enhanced and calcification be hindered by OA under constant indoor light, fluctuation of solar radiation with ultraviolet irradiances might offset such effects. In this study, when a calcifying and a non calcifying strain of Emiliania huxleyi were grown at 2 CO2 concentrations (low CO2 [LC] 395 uatm; high CO2 [HC] 1000 uatm) under different levels of incident solar radiation in the presence of ultraviolet radiation (UVR) HC and increased levels of solar radiation acted synergistically to enhance the growth in the calcifying strain but not in the non calcifying strain. HC enhanced the particulate organic carbon (POC) and nitrogen (PON) productions in both strains, and this effect was more obvious at high levels of solar radiation. While HC decreased calcification at low solar radiation levels, it did not cause a significant effect at high levels of solar radiation, implying that a sufficient supply of light energy can offset the impact of OA on the calcifying strain. Our data suggest that increased light exposure, which is predicted to happen with shoaling of the upper mixing layer due to progressive warming, could counteract the impact of OA on coccolithophores distributed within this layer.
Peng Jin Jiancheng Ding Tao Xing Ulf Riebesell Kunshan Gao
130958182
Origins of the Solar Radiation Biases over the Southern Ocean in CFMIP2 Models
AbstractCurrent climate models generally reflect too little solar radiation over the Southern Ocean, which may be the leading cause of the prevalent sea surface temperature biases in climate models. The authors study the role of clouds on the radiation biases in atmosphere only simulations of the Cloud Feedback Model Intercomparison Project phase 2 (CFMIP2) as clouds have a leading role in controlling the solar radiation absorbed at those latitudes. The authors composite daily data around cyclone centers in the latitude band between 40deg and 70degS during the summer. They use cloud property estimates from satellite to classify clouds into different regimes, which allow them to relate the cloud regimes and their associated radiative biases to the meteorological conditions in which they occur. The cloud regimes are defined using cloud properties retrieved using passive sensors and may suffer from the errors associated with this type of retrievals. The authors use information from the Cloud Aerosol Lidar and I.
Alejandro Bodas-Salcedo K D Williams Mark A Ringer Isabelle Beau Jason N S Cole Jean-Louis Dufresne Tsuyoshi Koshiro Bjorn Stevens Zunya Wang Tokuta Yokohata
53451159
Responses of marine primary producers to interactions between ocean acidification, solar radiation, and warming
Anthropogenic CO2 is accumulating in the atmosphere and trapping reflected infrared radiation, resulting in warming of both terrestrial and ocean ecosystems. At the same time, the dissolution of CO2 into seawater is increasing surface ocean acidity, a process known as ocean acidification. Effects of ocean acidification on marine primary producers have been docu mented to be stimulative, inhibitive, or neutral. Elevated CO2 and reduced pH levels can interact with solar radiation, which fluctuates over different time scales from limiting to saturating or even stressful levels, to bring about synergistic, antagonistic, or balanced effects on marine primary producers at different depths or under changing weather conditions. However, shoaling of the upper mixed layer (enhanced stratification) due to ocean warming and freshening (rain, ice melt ing) can lead to additional photosynthetically active radiation (PAR) and ultraviolet (UV) expo sure, which can have both benefits and costs to photosynthetic organisms. Elevated CO2 concen trations under low or moderate levels of PAR have been shown to enhance photosynthesis or growth of both phytoplankton and macroalgae; excessive levels of PAR, however, can lead to additional inhibition of photosynthesis or growth under elevated CO2, and addition of UV radia tion (280 to 400 nm) can increase or down regulate such inhibition, since solar UV B (280 to 315 nm) radiation often harms algal cells, while UV A (315 to 400 nm) at moderate levels stimu lates photosynthetic carbon fixation in both phytoplankton and macroalgae. In view of warming effects, increased temperatures have been shown to enhance photorepair of UV damaged mole cules, though it simultaneously enhances respiratory carbon loss. The net effects of ocean acidifi cation on marine primary producers are therefore largely dependent on the photobiological con ditions (light limitation, light or UV stress) as well as interactions with rising temperature and other variables such as altered nutrient availability. Hence, feedbacks between changing carbon ate chemistry and solar radiation across the entire spectrum present complications to interpret and understand ocean acidification effects based on single factor experiments.
Kunshan Gao E Walter Helbling Donat-P Hader David A Hutchins
55612732
Effects of the diurnal cycle in solar radiation on the tropical Indian Ocean mixed layer variability during wintertime Madden Julian Oscillations
[1] The effects of solar radiation diurnal cycle on intraseasonal mixed layer variability in the tropical Indian Ocean during boreal wintertime Madden Julian Oscillation (MJO) events are examined using the HYbrid Coordinate Ocean Model. Two parallel experiments, the main run and the experimental run, are performed for the period of 2005 2011 with daily atmospheric forcing except that an idealized hourly shortwave radiation diurnal cycle is included in the main run. The results show that the diurnal cycle of solar radiation generally warms the Indian Ocean sea surface temperature (SST) north of 10 S, particularly during the calm phase of the MJO when sea surface wind is weak, mixed layer is thin, and the SST diurnal cycle amplitude (dSST) is large. The diurnal cycle enhances the MJO forced intraseasonal SST variability by about 20% in key regions like the Seychelles Chagos Thermocline Ridge (SCTR; 55 70 E, 12 4 S) and the central equatorial Indian Ocean (CEIO; 65 95 E, 3 S 3 N) primarily through nonlinear rectification. The model also well reproduced the upper ocean variations monitored by the CINDY/DYNAMO field campaign between September November 2011. During this period, dSST reaches 0.7 C in the CEIO region, and intraseasonal SST variability is significantly amplified. In the SCTR region where mean easterly winds are strong during this period, diurnal SST variation and its impact on intraseasonal ocean variability are much weaker. In both regions, the diurnal cycle also has a large impact on the upward surface turbulent heat flux QT and induces diurnal variation of QT with a peak to peak difference of O(10 W m 2
Yuanlong Li Weiqing Han Toshiaki Shinoda Chunzai Wang Ren-Chieh Lien James N Moum Jih-Wang Aaron Wang
140691118
The Surface Downwelling Solar Radiation Surplus over the Southern Ocean in the Met Office Model: The Role of Midlatitude Cyclone Clouds
AbstractThe authors study the role of clouds in the persistent bias of surface downwelling shortwave radiation (SDSR) in the Southern Ocean in the atmosphere only version of the Met Office model. The reduction of this bias in the atmosphere only version is important to minimize sea surface temperature biases when the atmosphere model is coupled to a dynamic ocean. The authors use cloud properties and radiative fluxes estimates from the International Satellite Cloud Climatology Project (ISCCP) and apply a clustering technique to classify clouds into different regimes over the Southern Ocean. Then, they composite the cloud regimes around cyclone centers, which allows them to study the role of each cloud regime in a mean composite cyclone. Low and midlevel clouds in the cold air sector of the cyclones are responsible for most of the bias. Based on this analysis, the authors develop and test a new diagnosis of shear dominated boundary layers. This change improves the simulation of the SDSR through a better s.
Alejandro Bodas-Salcedo K D Williams Paul R Field Adrian P Lock
18670385
Penetration of UV visible solar radiation in the global oceans: Insights from ocean color remote sensing
NASA; JPSS VIIRS; National Natural Science Foundation of China [41071223, 40976068, 41121091] Ministry of Science and Technology of China [2013BAB04B00] CNRS; INSU
Zhongping Lee Chuanmin Hu Shaoling Shang Keping Du Marlon Lewis Robert Arnone Robert J W Brewin
3127408
Modeling polarized solar radiation from the ocean atmosphere system for CLARREO inter calibration applications
Reflected solar radiance from the Earth atmosphere system is polarized. Radiance measurements can be affected by light's state of polarization if the radiometric sensor has polarization dependence. To enable the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission for inter calibration of the imagers with polarization dependence, such as the MODIS, the polarization state of the light must be known with sufficient accuracy. For this purpose, the polarized solar radiation from the ocean atmosphere system is studied with an adding doubling radiative transfer model (ADRTM) The Cox Munk ocean wave slope distribution model is used in calculation of the reflection matrix of a wind ruffled ocean surface. An empirical foam spectral reflectance model and an empirical spectral reflectance model for water volume below the surface are integrated in the ocean surface model. Solar reflectance from the ADRTM is compared with that from the discrete ordinate radiative transfer (DISORT) model. Sensitivity studies are conducted for various ocean surface and atmospheric conditions for the stratification of polarization distribution models (PDMs) which are to be used in the inter calibration of the polarization sensitive imager measurements with the CLARREO data. This report presents the first accurate approach for making the spectral PDMs over broad solar spectra, which cannot be achieved by empirical PDMs based on the data from polarimetric sensors.
W Y Sun Constantine Lukashin
220626767
Modeling polarized solar radiation from ocean atmosphere system for CLARREO inter calibration applications
Abstract. Reflected solar radiance from the Earth atmosphere system is polarized. Radiance measurements can be affected by light's state of polarization if the radiometric sensor has polarization dependence. To enable the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission for inter calibration of the imagers with polarization dependence, such as the MODIS, the polarization state of the light must be known with sufficient accuracy. For this purpose, the polarized solar radiation from the ocean atmosphere system is studied with an adding doubling radiative transfer model (ADRTM) The Cox Munk ocean wave slope distribution model is used in calculation of the reflection matrix of a wind ruffled ocean surface. An empirical foam spectral reflectance model and an empirical spectral reflectance model for water volume below the surface are integrated in the ocean surface model. Solar reflectance from the ADRTM is compared with that from the discrete ordinate radiative transfer (DISORT) model. Sensitivity studies are conducted for various ocean surface and atmospheric conditions for the stratification of polarization distribution models (PDMs) which are to be used in the inter calibration of the polarization sensitive imager measurements with the CLARREO data. This report presents the first accurate approach for making the spectral PDMs over broad solar spectra, which cannot be achieved by empirical PDMs based on the data from polarimetric sensors.
W Y Sun Constantine Lukashin
44002028
Using Satellite Ocean Color Data to Derive an Empirical Model for the Penetration Depth of Solar Radiation (Hp) in the Tropical Pacific Ocean
AbstractSatellite based ocean color measurements indicate clear evidence for bioclimate interactions in the tropical Pacific associated with El Nino Southern Oscillation (ENSO) Recent modeling studies have demonstrated that ocean biology can potentially affect the climate through the penetration depth of solar radiation in the upper ocean (Hp) a primary parameter in coupling biology to physics in the ocean. At present, interannual variability in Hp and its related bioclimate feedback effects have not been adequately represented in coupled ocean atmosphere models. In this work, chlorophyll (Chl) concentration data from the Sea viewing Wide Field of view Sensor (SeaWiFS) available since 1997, are used to characterize interannual Hp variability in the tropical Pacific and to quantify its relationships with physical fields, including sea surface temperature (SST) and sea level (SL) It is found that interannual Hp variability is dominated by ENSO signals, with the largest variability located in the central.
Rong-Hua Zhang Dake Chen Guihua Wang