scholarly journals Variations in Short Wave Radiation and Ocean Temperature in the Tropical Indian Ocean

2021 ◽  
Vol 10 (2) ◽  
pp. 171-179
Author(s):  
Ahmad Fadlan ◽  
Muchammad Rizki ◽  
Tomi Ilham Pahlewi ◽  
Mohammad Ridwan Nur Prasetyo ◽  
Fajar Masan Bali ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Time Lag ◽  
Tropical Indian Ocean ◽  
Temporal Variations ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Sea Temperature ◽  
East Indian ◽  
Different Response

The purpose of this study was to know the results of the relation between short wave radiation (SWR) and sea temperature. This study used data of SWR and sea temperature from RAMA buoy which part of the data was obtained by the INA-PRIMA 2019. Besides, the SWR and Sea Temperature model data from ERA-5 and Copernicus were required to see these spatial and temporal variations. Diurnal analysis to determine the sea temperature responds to SWR parameters. While monthly analysis to see the variations of SWR and the sea temperature during Indian Ocean Dipole (IOD). The results show that there is a different response at sea temperature for each layer to the SWR parameter in diurnal. SWR can affect sea temperatures until 20 meters of depth. There is a time lag between 2 and 3 hours when the sun heats the sea until the sea surface temperature increases. The 20 meters of depth has a lag time until 4 hours. As for 40 to 80 meters of depth, the sea temperature was not longer responded by SWR, and the temperature is changed by the strength of these mixing.Warm pools are generally located in East Indian Ocean and the high SWR were very strong in West Indian Ocean along an anual.

scholarly journals Evaluating the Effects of Façade Greening on Human Bioclimate in a Complex Urban Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Britta Jänicke ◽  
Fred Meier ◽  
Marie-Therese Hoelscher ◽  
Dieter Scherer
Keyword(s):  
Heat Stress ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Long Wave ◽  
Building Facades ◽  
Urban Heat ◽  
The Mean ◽  
Human Bioclimate ◽  
Radiant Temperature

The evaluation of the effectiveness of countermeasures for a reduction of urban heat stress, such as façade greening, is challenging due to lacking transferability of results from one location to another. Furthermore, complex variables such as the mean radiant temperature(Tmrt)are necessary to assess outdoor human bioclimate. We observedTmrtin front of a building façade in Berlin, Germany, which is half-greened while the other part is bare.Tmrtwas reduced (mean 2 K) in front of the greened compared to the bare façade. To overcome observational shortcomings, we applied the microscale models ENVI-met, RayMan, and SOLWEIG. We evaluated these models based on observations. Our results show thatTmrt(MD = −1.93 K) and downward short-wave radiation (MD = 14.39 W/m2) were sufficiently simulated in contrast to upward short-wave and long-wave radiation. Finally, we compare the simulated reduction ofTmrtwith the observed one in front of the façade greening, showing that the models were not able to simulate the effects of façade greening with the applied settings. Our results reveal that façade greening contributes only slightly to a reduction of heat stress in front of building façades.

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

Short-wave radiation from a tube with a gas screen

1974 ◽  
Vol 20 (4) ◽  
pp. 434-438
Author(s):  
E. M. Golubev ◽  
N. N. Ogurtsova ◽  
I. V. Podmoshenskii ◽  
P. N. Rogovtsev
Keyword(s):  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Gas Screen

scholarly journals Evaluation of the heat balance components over the Baltic Sea using four gridded meteorological databases and direct observations

2005 ◽  
Vol 36 (4-5) ◽  
pp. 381-396 ◽  
Author(s):  
A. Rutgersson ◽  
A. Omstedt ◽  
Y. Chen
Keyword(s):  
Baltic Sea ◽  
Short Wave ◽  
Heat Fluxes ◽  
Wave Radiation ◽  
Turbulent Heat ◽  
The Baltic Sea ◽  
Short Wave Radiation ◽  
Turbulent Heat Fluxes ◽  
The Baltic ◽  
The Heat Balance

In this paper, which reports on part of the BALTEX project, various components of the heat balance over the Baltic Sea are calculated using a number of gridded meteorological databases. It is the heat exchange between the Baltic Sea surface and the atmosphere that is of interest. The databases have different origins, comprising synoptic data, data re-analysed with a 3D assimilation system, an ocean model forced with gridded synoptic data, ship data and satellite data. We compared the databases and found that the greatest variation between them is in the long- and short-wave radiation values. However, considerable upward long-wave radiation is followed by considerable downward short-wave radiation, so the total radiation component is partly compensated for in the total budget. The variation in the total heat transport in the databases therefore appears smaller (1.5±3 W m−2) as the average and one standard deviation. The turbulent heat fluxes estimated from satellite data have very low values; this can largely be explained by the method of calculating air temperature, which also produces an unrealistic stratification over the Baltic Sea. The ERA40 data was compared with measured values: there, we found a certain land influence even in the centre of the Baltic proper. The indicated turbulent heat fluxes were too large, mainly in the fall and winter, and the sensible heat flux was too large in a downward direction in spring and summer.

Cloud effects on surface radiation balance at Helheim and Jakobshavn Glaciers (Greenland) using ground-based observations 

2021 ◽  
Author(s):  
Georges Djoumna ◽  
Sebastian H. Mernild ◽  
David Holland
Keyword(s):  
Short Wave ◽  
Surface Radiation ◽  
Radiation Budget ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Short Wave Radiation ◽  
Radiative Fluxes ◽  
Long Wave ◽  
Transmittance Factor ◽  
Cloud Metrics

<p>The surface radiation budget is an essential component of the total energy exchange between the atmosphere and the Earth’s surface. Measurements of radiative fluxes near/on ice surfaces are sparse in the polar regions, including on the Greenland Ice Sheet (GrIS), and the effects of cloud on radiative fluxes are still poorly studied. In this work, we assess the impacts of cloud on radiative fluxes using two metrics: the longwave-equivalent cloudiness, derived from long-wave radiation measurements, and the cloud transmittance factor, obtained from short-wave radiation. The metrics are applied to radiation data from two automatic weather stations located over the bare ground near the ice front of Helheim (HG) and Jakobshavn Isbræ (JI) on the GrIS. Comparisons of meteorological parameters, surface radiation fluxes, and cloud metrics show significant differences between the two sites. The cloud transmittance factor is higher at HG than at JI, and the incoming short-wave radiation in the summer at HG is 50.0 W m−2 larger than at JI. Cloud metrics derived at the two sites reveal   a high dependency on the wind direction. The total cloud radiative effect (CREnet) generally increases during melt season at the two stations due to long-wave CRE enhancement by cloud fraction.  CREnet decreases from May to June and increases afterward, due to the strengthened short-wave CRE. The annually averaged CREnet were 3.0 ± 7.4 W m-2 and 1.9 ± 15.1 W m−2 at JI and HG.  CREnet estimated from AWS indicates that clouds cool the JI and HG during melt season at different rates.</p>

Study of the sea ice impact on primary production in the Barents and Kara Seas in past and future climates

2021 ◽  
Author(s):  
Stanislav D. Martyanov ◽  
Anton Y. Dvornikov ◽  
Vladimir A. Ryabchenko ◽  
Dmitry V. Sein
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Marine Ecosystem ◽  
Short Wave ◽  
Steering Committee ◽  
Wave Radiation ◽  
Primary Role ◽  
Short Wave Radiation ◽  
Ocean Carbon ◽  
Barents And Kara Seas

<p>A regional coupled eco-hydrodynamic model of the Barents and Kara Seas based on the MITgcm has been developed. The biogeochemical module is based on a 7-component model of pelagic biogeochemistry including the ocean carbon cycle. This regional model allows revealing and explaining the main mechanisms of the interaction between marine dynamic and biogeochemical processes in the Barents and Kara Seas under a changing climate. We present the main results of simulations for the past (1975-2005) and future (2035-2065) climate.</p><p>A clear relationship between the marginal ice zone area and primary production has been obtained, proving the importance of this zone in the functioning of the marine ecosystem. The interannual variability of the integrated primary production and the total sea ice area demonstrates an antiphase behavior, which means that the reduced sea ice cover area in the previous winter is one of the main reasons for the increase in primary production in the current year.</p><p>The model simulations demonstrate that, of all the external factors, sea ice area plays a primary role in the formation of primary production: in the overwhelming majority of cases, the contribution of the ice area prevails, and the pattern "more ice - less primary production" and vice versa is fulfilled in the Barents and Kara Seas. The effect of a decrease of incoming short-wave radiation becomes significant only when a significant decrease of the ice area occurs.</p><p>Compared to the period 1975-2005, the simulated total primary production in the Barents and Kara Seas is much higher for the period 2035-2065, while the sea ice area significantly decreases.</p><p>A regression dependence has been obtained for the total annual primary production as a function of sea ice area and incoming short-wave radiation. Its validity is verified for both past (dependent) and future (independent) climatic periods. It justifies the use of such simple statistical model for quick estimates of the primary production in the Barents and Kara Seas.</p><p>Acknowledgements: The research was performed in the framework of the state assignment of the Ministry of Science and Higher Education of Russia (theme No. 0128-2021-0014). This work used resources of the Deutsches Klimarechenzentrum (DKRZ) granted by its Scientific Steering Committee (WLA) under project ID ba1206.</p>

scholarly journals Prediction of Radiation Frost Using Support Vector Machines Based on Micrometeorological Data

2019 ◽  
Vol 10 (1) ◽  
pp. 283
Author(s):  
Yongzong Lu ◽  
Yongguang Hu ◽  
Pingping Li ◽  
Kyaw Tha Paw U ◽  
Richard L. Snyder
Keyword(s):  
Yangtze River ◽  
Prediction Accuracy ◽  
Short Wave ◽  
Yangtze River Delta ◽  
Wave Radiation ◽  
Support Vector ◽  
Short Wave Radiation ◽  
Long Wave ◽  
Vector Machines ◽  
Long Wave Radiation

Radiation frost happens frequently in the Yangtze River Delta region, which causes high economic loss in agriculture industry. It occurs because of heat losses from the atmosphere, plant and soil in the form of radiant energy, which is strongly associated with the micrometeorological characteristics. Multidimensional and nonlinear micrometeorological data enhances the difficulty in predicting the radiation frost. Support vector machines (SVMs), a type of algorithms, can be supervised learning which widely be employed for classification or regression problems in research of precision agriculture. This paper is the first attempt of using SVMs to build prediction models for radiation frost. Thirty-two kinds of micrometeorological parameters, such as daily mean temperature at six heights (Tmean0.5, Tmean1.5, Tmean2.0, Tmean3.0, Tmean4.5 and Tmean6.0), daily maximum and minimum temperatures at six heights (Tmax0.5, Tmax1.5, Tmax2.0, Tmax3.0, Tmax4.5 and Tmax6.0, and Tmin0.5, Tmin1.5, Tmin2.0, Tmin3.0, Tmin4.5 and Tmin6.0), daily mean relative humidity at six heights (RH0.5, RH1.5, RH2.0, RH3.0, RH4.5 and RH6.0), net radiation (Rn), downward short-wave radiation (Rsd), downward long-wave radiation (Rld), upward long-wave radiation (Rlu), upward short-wave radiation (Rsu), soil temperature (Tsoil) and soil heat flux (G) and daily average wind speed (u) were collected from November 2016 to July 2018. Six combinations inputs were used as the basis dataset for testing and training. Three types of kernel functions, such as linear kernel, radial basis function kernel and polynomial kernel function were used to develop the SVMs models. Five-fold cross validation was conducted for model fitting on training dataset to alleviate over-fitting and make prediction results more reliable. The results showed that an SVM with the radial basis function kernel (SVM-BRF) model with all the 32 micrometeorological data obtained high prediction accuracy in training and testing sets. When the single type of data (temperature, humidity and radiation data) was used for the SVM without any functions, prediction accuracy was better than that with functions. The SVM-BRF model had the best prediction accuracy when using the multidimensional and nonlinear micrometeorological data. Considering the complexity level of the model and the accuracy of prediction, micrometeorological data at the canopy height with the SVM-BRF model has been recommended for radiation frost prediction in Yangtze River Delta and probably could be applied in elsewhere with the similar terrains and micro-climates.

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