PENERAPAN PEMBELAJARAN CONTEXTUAL TEACHING AND LEARNING (CTL) TERHADAP HASIL BELAJAR SISWA PADA POKOK BAHASAN CARA-CARA PENANGANAN LIMBAH DI SMK CARUBAN NAGARI KECAMATAN DUKUPUNTANG KABUPATEN CIREBON

JUBAEDAH : Penerapan Pembelajaran Contexstual Teaching And Learning (CTL) Terhadap Hasil Belajar Siswa Pada Pokok Bahasan Cara-Cara Penanganan Limbah Di SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon. Proses pembelajaran Contexstual Teaching and Learning (CTL) merupakan pembelajaran yang membantu guru antara materi yang diajarkan dengan situasi dunia nyata siswa dan mendorong siswa membuat hubungan antara pengetahuan yang dimiliki dengan penerapannya dalam kehidupannya sebagai anggota keluarga dan masyarakat. Dengan pemahaman ini, hasil belajar diharapkan lebih bermakna bagi siswa. Untuk mengatasi masalah tersebut, seorang guru dapat menggunakan pembelajaran Contexstual Teaching and Learning (CTL) dalam menyampaikan materi khususnya IPA (Ilmu Pengetahuan Alam). Penelitian ini bertujuan untuk mengkaji bagaimana penerapan pembelajaran dengan menggunakan contextual teaching and learning (CTL) terhadap hasil belajar siswa pada pokok bahasan cara-cara penanganan limbah di SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon.Untuk mengkaji apakah ada perbedaan hasil belajar yang menggunakan contextual teaching and learning (CTL) dan pembelajaran tidak menggunakan contextual teaching and learning (CTL) terhadap hasil belajar siswa antara kelas eksperimen dengan kelas kontrol pada pokok bahasan cara-cara penanganan limbah.Untuk mengkaji bagaimana respon siswa terhadap penerapan pembelajaran contextual teaching and learning (CTL) pada pokok bahasan cara-cara penanganan. Populasi dalam penelitian ini adalah seluruh siswa SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon. Adapun sampel dalam penelitian ini yakni diambil kelas XIa sebagai kelas kontrol dan kelas XI b eksperimen dalam penelitian dan masing-masing kelas berjumlah 30 siswa. Dalam pengumpulan data, penulis menggunakan teknik tes, angket dan observasi. Setelah data diperoleh dari hasil penelitian maka data tersebut dianalisis dengan cara analisis kuantitaf, sebelum penulis melakukan uji instrumen untuk memperoleh validitas menggunkan master templet. Kesimpulam dari penelitian ini menunjukkan bahwa dalam proses pembelajaran yang dilakukan dalam kelas dengan menggunakan Contexstual Teaching and Learning (CTL) mendapat nilai minimum 11 mengalami peningkatan sampai nilai 19 dengan nilai rata-rata 21.13. Hal ini dapat dilihat dari pada gain dari tiap kelas. Dari data yang diperoleh dari gain menunjukan bahwa nilai t diperoleh sebesar = -6,323 dengan derajat kebebasan (df) = n1 + n2 – 2 = (30 + 30 – 2 =58 ).α = 0,05 diperoleh Sig.0,000. karena Sig.0,000 < 0,05 maka dapat disimpulkan bahwa Ha diterima. Respon siswa terhadap penerapan pembelajaran contextual teaching and learning (CTL) yang menjawab ya sebesar 49 % termasuk kriteria cukup, yang menjawab kadang-kadang sebesar 39% kriteria rendah dan yang menjawab tidak sedikit sekali 12% termasuk kriteria rendah sekali

Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean

Source at http://dx.doi.org/10.1002/2016JC011779 This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. The average upward turbulent diffusive nitrate flux across the seasonal nitracline during the Arctic summer season is derived, with average values of 0.3 and 0.7 mmol m−2 d−1 for stations with and without ice cover, respectively. The increase under ice-free conditions is attributed to different patterns of stratification under sea ice versus open water. The nitrate flux obtained from microstructure measurements lacked a seasonal signal. However, bottle incubations indicate that August nitrate uptake was reduced by more than an order of magnitude relative to the May values. It remains inconclusive whether the new production was limited by an unidentified factor other than NO3− supply in late summer, or the uptake was underestimated by the incubation method.</p

Seasonality of the Physical and Biogeochemical Hydrography in the Inflow to the Arctic Ocean Through Fram Strait

Eastern Fram Strait and the shelf slope region north of Svalbard is dominated by the advection of warm, salty and nutrient-rich Atlantic Water (AW). This oceanic heat contributes to keeping the area relatively free of ice. The last years have seen a dramatic decrease in regional sea ice extent, which is expected to drive large increases in pelagic primary production and thereby changes in marine ecology and nutrient cycling. In a concerted effort, we conducted five cruises to the area in winter, spring, summer and fall of 2014, in order to understand the physical and biogeochemical controls of carbon cycling, for the first time from a year-round point of view. We document (1) the offshore location of the wintertime front between salty AW and fresher Surface Water in the ocean surface, (2) thermal convection of Atlantic Water over the shelf slope, likely enhancing vertical nutrient fluxes, and (3) the importance of ice melt derived upper ocean stratification for the spring bloom timing. Our findings strongly confirm the hypothesis that this “Atlantification,” as it has been called, of the shelf slope area north of Svalbard resulting from the advection of AW alleviates both nutrient and light limitations at the same time, leading to increased pelagic primary productivity in this region

Nutrients vs. turbulence, and the future of Arctic Ocean primary production

Poster no. B7 from Forum for Arctic Modeling & Observational Synthesis (Woods Hole Oceanographic Institution, 2-4 November 2016.This poster presents estimates of nitrate fluxes in the Arctic Ocean and speculates on the associated primary production in a future climate

Carbon export in the seasonal sea ice zone north of Svalbard from winter to late summer

Phytoplankton blooms in the Arctic Ocean's seasonal sea ice zone are expected to start earlier and occur further north with retreating and thinning sea ice cover. The current study is the first compilation of phytoplankton bloom development and fate in the seasonally variable sea ice zone north of Svalbard from winter to late summer, using short-term sediment trap deployments. Clear seasonal patterns were discovered, with low winter and pre-bloom phytoplankton standing stocks and export fluxes, a short and intense productive season in May and June, and low Chl a standing stocks but moderate carbon export fluxes in the autumn post-bloom conditions. We observed intense phytoplankton blooms with Chl a standing stocks of >350 mg m−2 below consolidated sea ice cover, dominated by the prymnesiophyte Phaeocystis pouchetii. The largest vertical organic carbon export fluxes to 100 m, of up to 513 mg C m−2 day−1, were recorded at stations dominated by diatoms, while those dominated by P. pouchetii recorded carbon export fluxes up to 310 mg C m−2 day−1. Fecal pellets from krill and copepods contributed a substantial fraction to carbon export in certain areas, especially where blooms of P. pouchetii dominated and Atlantic water advection was prominent. The interplay between the taxonomic composition of protist assemblages, large grazers, distance to open water, and Atlantic water advection was found to be crucial in determining the fate of the blooms and the magnitude of organic carbon exported out of the surface water column. Previously, the marginal ice zone was considered the most productive region in the area, but our study reveals intense blooms and high export events in ice-covered waters. This is the first comprehensive study on carbon export fluxes for under-ice phytoplankton blooms, a phenomenon suggested to have increased in importance under the new Arctic sea ice regime

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 40850, doi:10.1038/srep40850.The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m−2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.This study was supported by the Centre for Ice, Climate and Ecosystems (ICE) at the Norwegian Polar Institute, the Ministry of Climate and Environment, Norway, the Research Council of Norway (projects Boom or Bust no. 244646, STASIS no. 221961, CORESAT no. 222681, CIRFA no. 237906 and AMOS CeO no. 223254), and the Ministry of Foreign Affairs, Norway (project ID Arctic), the ICE-ARC program of the European Union 7th Framework Program (grant number 603887), the Polish-Norwegian Research Program operated by the National Centre for Research and Development under the Norwegian Financial Mechanism 2009–2014 in the frame of Project Contract Pol-Nor/197511/40/2013, CDOM-HEAT, and the Ocean Acidification Flagship program within the FRAM- High North Research Centre for Climate and the Environment, Norway

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic

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Vertical nitrate fluxes in the Arctic Ocean

Upward mixing of remineralized nutrients is essential for photosynthesis in the upper ocean. Weak vertical mixing, which restricts nutrient supply, and sea ice, which leads to low light levels, conspire to severely inhibit marine primary productivity in the Arctic Ocean. However, little has been known about their relative contributions. No large-scale quantitative estimates of the vertical nutrient supply had previously been presented, which has impeded an understanding of its role in shaping the ecology and carbon cycle of the Arctic Ocean. In order to estimate the vertical flux of nitrate into the surface layer in contrasting hydrographic and dynamic regimes, profiles of turbulent microstructure and nitrate concentrations were measured as part of a number of cruises and ice camps in the area extending from eastern Fram Strait into the Nansen Basin. These have been supplemented with obervations of the seasonal nutrient cycle at a mooring in the same area, and a reanalysis of available data on nitrate concentrations and turbulent mixing in other parts of the central Arctic Ocean. Hydrography was found to be the biggest driver of variability in nitrate fluxes. Strong stratification, wherever encountered, restricted nitrate supply, often in concert with concurrently weak turbulent mixing, both in the seasonal nitracline (0.3–0.7 mmol N m-2 d-1) and the deep basin (0.01–0.2 mmol N m-2 d-1). Thus deep winter mixing supplies the bulk of the nitrate pool on the relatively productive shelves (e.g. 2.5 mmol N m-2 d-1 in the inflow of Atlantic Water during winter), but in the strongly stratified Canadian Basin, fluxes are low year-round (on the order of 0.01 mmol N m-2 d-1) and place a tight limit on new production. Only the weakly stratified Atlantic derived water in the Nansen Basin close to Fram Strait seems to have a certain potential to support future increases in new production under a seasonal ice cover

Regional patterns in current and future export production in the central Arctic Ocean quantified from nitrate fluxes

Due to severe nutrient and light limitation, the central Arctic Ocean has been characterized as a region of low primary productivity, with high retention of carbon in the surface waters. Using an in-depth analysis of published and new measurements of turbulent microstructure and high-resolution profiles of nitrate concentration, we reassess the vertical supply of nitrate to the Polar Mixed Layer and the associated export of particulate organic matter across the nitracline. We estimate annual export production to be approximately 1.5–3 g C m−2, but regional differences in both current and future potential of export production are large, with the eastern Arctic being least constrained by vertical nutrient supply and the western Arctic the most. Future changes in export production are assessed using a 1-D budget model; increases in the Atlantic sector are possibly compensated by decreases in the rest of the central Arctic Ocean such that the net change might be insignificant

Turbulent upper-ocean mixing affected by meltwater layers during Arctic summer

Every summer, intense sea ice melt around the margins of the Arctic pack ice leads to a stratified surface layer, potentially without a traditional surface mixed layer. The associated strengthening of near-surface stratification has important consequences for the redistribution of near-inertial energy, ice–ocean heat fluxes, and vertical replenishment of nutrients required for biological growth. The authors describe the vertical structure of meltwater layers and quantify their seasonal evolution and their effect on turbulent mixing in the oceanic boundary layer by analyzing more than 450 vertical profiles of velocity microstructure in the seasonal ice zone north of Svalbard. The vertical structure of the density profiles can be summarized by an equivalent mixed layer depth hBD, which scales with the depth of the seasonal stratification. As the season progresses and melt rates increase, hBD shoals following a robust pattern, implying stronger vertical stratification, weaker vertical eddy diffusivity, and reduced vertical extent of the mixing layer, which is bounded by hBD. Through most of the seasonal pycnocline, the vertical eddy diffusivity scales inversely with buoyancy frequency (Kρ ∝ N−1). The presence of mobile sea ice alters the magnitude and vertical structure of turbulent mixing primarily through stronger and shallower stratification, and thus vertical eddy diffusivity is greatly reduced under sea ice. This study uses these results to develop a quantitative model of surface layer turbulent mixing during Arctic summer and discuss the impacts of a changing sea ice cover