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1
Ilahude, Delyuzar. "MAGNETIC ANOMALY PATTERNS USING TREND SURFACE ANALYSIS APPLICATION (TSA) ON MARINE GEOLOGY MAPPING IN THE BALIKPAPAN WATERS." BULLETIN OF THE MARINE GEOLOGY 27, no. 1 (February 15, 2016): 19. http://dx.doi.org/10.32693/bomg.27.1.2012.42.
Повний текст джерелаАнотація:
The application of Trend Surface Analysis (TSA) method an geological and geophysical research in map sheets 1813-1814, Balikpapan Waters and its surrounding, shows the significant value of residual anomaly. The magnetic disseverance of regional and total anomaly value obtained the negative anomaly between -50 nT and -350 nT and positive anomaly between +50 nT and +400 nT. The contour of total and regional anomaly shows the magnetic properties of rocks which characterizes the geological arrangements of the research areas. Residual anomaly yielded from the 2nd order value of regional anomaly might be correlated with the formation of basin structures in the central and northern parts of research area, which is interpreted as a part of Kutai Basin.
Keywords : TSA method, magnetic anomaly, geology and geophisics, Balikpapan Waters.
Penerapan metode TSA dalam penelitian geologi dan geofisika di Lembar Peta 1813-1814, Perairan Balikpapan dan sekitarnya menunjukkan nilai anomali sisa yang cukup signifikan. Hasil pemisahan nilai anomali magnet regional dan anomaly total diperoleh nilai anomali yaitu antara -50 nT dan –350 nT dan anomali positif antara +50 nT dan +400 nT. Kontur anomali total dan anomali regional memperlihatkan sifat kemagnitan batuan yang mencirikan tatanan geologi daerah penelitian. Anomali sisa dihasilkan dari nilai anomali regional orde ke 2, kemungkinan berkaitan dengan pembentukan struktur cekungan di bagian tengah dan utara daerah penelitian yang ditafsirkan sebagai bagian dari Cekungan Kutai.
Kata kunci : metode TSA, anomali magnet, geologi dan geofisika, Perairan Balikpapan.
2
Ilahude, Delyuzar, and Beben Rachmat. "POLA ANOMALI MAGNET LOKAL DARI APLIKASI TREND SURFACE ANALYSIS (TSA) PADA PEMETAAN GEOLOGI KELAUTAN BERSISTEM DI PERAIRAN SELAT MALAKA SUMATERA UTARA." JURNAL GEOLOGI KELAUTAN 9, no. 2 (February 16, 2016): 109. http://dx.doi.org/10.32693/jgk.9.2.2011.204.
Повний текст джерелаАнотація:
Analisis intensitas magnet dari penerapan metode TSA orde ke 2 menunjukkan nilai anomali lokal yang cukup signifikan dari pemisahan nilai anomali magnet total di perairan Selat Malaka. Kontur anomali lokal yang dihasilkan diduga berkaitan dengan pola struktur geologi busur belakang Sumatera Utara.
Kata kunci : anomali lokal, metode TSA
Analysis of magnetic intensity using 2nd orde of the TSA method shows a significant value of local anomaly from the separation of total magnetic anomaly value in the Malaka Strait waters. Contour of the local anomaly resulted is assumed to be correlated with the geological structure pattern of back arc of North Sumatera.
Keyword : local anomaly, TSA method
3
Cai, Jiaxiong. "Surface Magnetic Anomaly Triangulation Inversion." International Journal of Geosciences 10, no. 02 (2019): 160–72. http://dx.doi.org/10.4236/ijg.2019.102010.
Повний текст джерела
4
Subagio, Subagio, and Tatang Patmawidjaya. "POLA ANOMALI BOUGUER DAN ANOMALI MAGNET DAN KAITANNYA DENGAN PROSPEK SUMBER DAYA MINERAL DAN ENERGI DI PULAU LAUT, PULAU SEBUKU DAN SELAT SEBUKU, KALIMANTAN SELATAN." JURNAL GEOLOGI KELAUTAN 11, no. 3 (February 16, 2016): 115. http://dx.doi.org/10.32693/jgk.11.3.2013.236.
Повний текст джерелаАнотація:
Anomali Bouguer Pulau Laut, Pulau Sebuku, dan Selat Sebuku dapat dikelompokkan menjadi dua wilayah anomali meliputi anomali berpola melingkar dengan kisaran nilai dari 40 hingga 64 mGal, dan anomali berpola lurus dengan kisaran nilai 40 hingga 50 mGal. Anomali magnet di daerah ini bervariasi dari -700 hingga 1600 nT, membentuk pola tinggian dan rendahan. Anomali Bouguer berpola melingkar dengan kisaran nilai 45-64 mGal mencerminkan batuan ultrabasa yang relatif mendekati permukaan. Batuan ultrabasa yang tersingkap di permukaan dicirikan oleh anomali magnet tinggi. Anomali Bouguer berpola kontur lurus sejajar menunjukkan sesar naik maupun sesar turun yang terdapat di daerah tersebut. Sesar naik yang berkembang di daerah penelitian umumnya terdapat di Pegunungan Meratus yang mempunyai mendala geologi sama. Anomali Bouguer dan anomali magnet rendah mencerminkan cekungan sedimen. yang diakibatkan oleh adanya gaya tarikan yang pernah ada. Batuan terobosan yang dijumpai, diduga terbentuk bersamaan dengan periode gaya tarikan ini. Serangkaian proses tektonik yang hasilnya terekam pada anomali Bouguer, anomali magnet, dan singkapan batuan memberi implikasi kemungkinan terdapatnya sumber daya energi dan mineral di daerah penelitian. Mineralisasi logam diperkirakan dapat dijumpai di sekitar daerah terobosan. Bijih besi, nikel, dan kromit kemungkinan terdapat di daerah ultra-mafik, sedangkan batubara di daerah cekungan sedimen.
Kata kunci : Anomali Bouguer, anomali magnet, sumber daya energi dan mineral, sesar naik dan sesar turun.
Bouguer anomaly of the Laut Island, Sebuku Island, and The Sebuku Strait can be grouped into two anomaly groups covering the circular pattern anomaly with range from 40 to 64 mGals, and the straight pattern with range of values from 40 to 50 mGals. The range of magnetic anomalies in the study area area from -700 to 1600 nT, forming high and low anomay patterns. The circular pattern of the Bouguer anomalies with range from 45 to 64 mGals reflects that the ultramafic rocks relatively close to the surface, while exposed ultrabasic rocks are indicated by high magnetic anomalies. Paralled pattern contour of Bouguer anomaly show a thrust faults and normal faults in this area. Thrust faults of commonly develop in Meratus Mountaint that has the same geological setting. The low Bouguer and magnetic anomalies reflect a sedimentary basin caused by previous tensional force. The intrusion rocks found in the study area suggest to be formed together with this tensional force period. A series of tectonic events recorded in Bougue anomaly, magnetic anomaly, and out crops gave the implication the possibility the present of energy and mineral resources in the study area. Metal mineralization suggests to be found in the intrusion area. Irons, nickels and chromites supposed can be found in the ulta-mafic area, while coal can be found in the sedimentary basin.
Keywords : Bouguer anomalies, magnetic anomalies, energy and mineral resources, thrust and normal faults.
5
Kim, Yong W. "Development of Near-Surface Composition Anomaly." International Journal of Thermophysics 25, no. 2 (March 2004): 575–86. http://dx.doi.org/10.1023/b:ijot.0000028491.49665.c4.
Повний текст джерела
6
Schwenk, J. Tyler, Steven D. Sloan, Julian Ivanov, and Richard D. Miller. "Surface-wave methods for anomaly detection." GEOPHYSICS 81, no. 4 (July 2016): EN29—EN42. http://dx.doi.org/10.1190/geo2015-0356.1.
Повний текст джерелаАнотація:
Perimeter-defense operations, geohazard assessment, and engineering characterization require the detection and localization of subsurface anomalies. Seismic waves incident upon these discontinuities generate a scattered wavefield. We have developed various surface-wave techniques, currently being fielded, that have consistently delivered accurate and precise results across a wide range of survey parameters and geographical locations. We use the multichannel analysis of surface waves approach to study the multimode Rayleigh wave, the backscatter analysis of surface waves (BASW) method to detect anomalies, 3D visualization for efficient seismic interpretation, BASW correlation for attribute analysis, and instantaneous-amplitude integration in the complex BASW method. Discrete linear moveout functions and [Formula: see text]-[Formula: see text] filter designs are optimized for BASW considering the fundamental and higher mode dispersion trends of the Rayleigh wave. Synthetic and field data were used to demonstrate multimode BASW and mode separation, which accentuated individual scatter events, and ultimately increased confidence in points of interest. Simple correlation algorithms between fundamental and higher-mode BASW data offer attribute analysis that limits the subjective interpretation of BASW images. Domain sorting and Hilbert transforms allow for 3D visualization and rapid interpretation of an anomaly’s wavefield phenomena within an amplitude cube. Furthermore, instantaneous-amplitude analysis can be incorporated into a more robust complex BASW method that forgives velocity-estimation inaccuracies, while requiring less rigorous preprocessing. Our investigations have suggested that a multifaceted surface-wave analysis provides a valuable tool for today’s geophysicists to fulfill anomaly-detection survey requirements.
7
Hulpke, E., and J. Lüdecke. "Surface phonon anomaly induced by adsorption." Journal of Electron Spectroscopy and Related Phenomena 64-65 (December 1993): 641–49. http://dx.doi.org/10.1016/0368-2048(93)80132-6.
Повний текст джерела
8
Ravat, D., K. A. Whaler, M. Pilkington, T. Sabaka, and M. Purucker. "Compatibility of high-altitude aeromagnetic and satellite-altitude magnetic anomalies over Canada." GEOPHYSICS 67, no. 2 (March 2002): 546–54. http://dx.doi.org/10.1190/1.1468615.
Повний текст джерелаАнотація:
Results from equivalent-source distributions derived jointly from high-altitude (average 4 km) aeromagnetic and Magsat-derived (average 400 km) magnetic anomalies over Canada indicate that long-wavelength components (500–2500 km) in these fields are extremely compatible with one another (with a correlation coefficient of 0.95). The jointly estimated anomaly field at the earth's surface can be used as a long-wavelength adjustment surface for regional near-surface magnetic anomaly compilations and in assessing the performance of other downward-continuation techniques. Because near-surface anomalies are not available over all regions of the world, we compare the jointly estimated anomaly field to the results of two different downward-continuation techniques: the evaluation of anomalies at the earth's surface from spherical harmonic coefficients derived from satellite-altitude data and the use of downward-continuation methods based on harmonic splines. Numerical and visual comparisons of these downward- continued fields with the jointly estimated anomaly field from the equivalent-source method indicate they are well correlated and could provide a useful method of deriving long-wavelength leveling surfaces for regional and worldwide magnetic anomaly maps.
9
Wahyuni, Silvia, and Marzuki Marzuki. "Analisis Anomali Temperatur Permukaan Tanah dan Awan Gempa Berkaitan dengan Gempa Palu 2018." Jurnal Fisika Unand 9, no. 3 (August 14, 2020): 352–59. http://dx.doi.org/10.25077/jfu.9.3.352-359.2020.
Повний текст джерелаАнотація:
Anomali temperatur permukaan tanah dan awan gempa yang berkaitan gempa bumi yang terjadi di Palu 28 September 2018 telah diteliti menggunakan data temperatur permukaan tanah dan permukaan air laut dari Moderate Resolution Imaging Spectroradiometer (MODIS) dan data awan dari satelit Multifunction Transport Satellite (MTSAT). Data temperatur udara dari European Centre for Medium Range Weather Forecasts (EMCWF) juga digunakan untuk memastikan bahwa anomali temperatur bukan disebabkan oleh aktivitas cuaca. Anomali temperature permukaan tanah diamati selama 5 tahun dari 2014-2018 dan awan gempa diamati 3 bulan sebelum terjadi gempa bumi. Penelitian ini menemukan adanya kenaikan temperatur permukaan tanah dan air laut sebagai prekursor gempa Palu 2018. Pada saat terjadi gempa kenaikan temperatur permukaan tanah pada siang hari sebesar 2,2 K melebihi batas nilai sebagai prekursor gempa bumi (2 K) tetapi kenaikan temperatur teramati setiap tahun. Selain itu, anomali temperatur permukaan laut hanya 0,25 K masih lebih kecil dari anomali sebagai prekursor gempa bumi (2 K). Selama itu tidak ditemukan juga adanya kemunculan awan gempa sebelum gempa terjadi. Dengan demikian gempa Palu 2018 tidak diiringi oleh kenaikan temperatur permukaan tanah dan air laut serta kemunculan awan gempa. Anomaly land surface temperature and earthquake cloud that related the 2018 Palu earthquake were examined using land and sea surface temperatures from Moderate Resolution Imaging Spectroradiometer (MODIS) and cloud from the Multifunction Transport Satellite (MTSAT) satellite data. Air temperature data from the European Center for Medium-Range Weather Forecasts (EMCWF) were also used to ensure that temperature anomalies are not caused by weather activity. Land surface temperature anomalies were observed for five years from 2014-2018, and earthquake clouds were observed for three months before the earthquake. This study find an increase in the surface temperature of land and seawater as a precursor to the 2018 Palu earthquake. During the earthquake, there was an increase in land surface temperature by 2,2 K, which exceeds the limit value of anomaly land surface temperature as an earthquake precursor ( 2 K), but such an increase is observed every year. In addition, sea surface temperature anomaly is only 0,25 K, which is much smaller than the value as an earthquake precursor ( 2 K). It was also found that there is no earthquake cloud before the Palu earthquake. Thus, the 2018 Palu earthquake was not accompanied by an increase in land and sea surface temperatures and the appearance of earthquake clouds.
10
Marpaung, Sartono, and Wawan K. Harsanugraha. "ANALYSIS OF SEA SURFACE HEIGHT ANOMALY CHARACTERISTICS BASED ON SATELLITE ALTIMETRY DATA (CASE STUDY: SEAS SURROUNDING JAVA ISLAND)." International Journal of Remote Sensing and Earth Sciences (IJReSES) 11, no. 2 (April 12, 2017): 137. http://dx.doi.org/10.30536/j.ijreses.2014.v11.a2611.
Повний текст джерелаАнотація:
Sea surface height anomaly is a oceanographic parameter that has spatial and temporal variability. This paper aims to determine the characters of sea surface height anomaly in the south and north seas of Java Island. To find these characters, a descriptive analysis of monthly anomaly data is performed spatially, zonally and temporally. Based on satellite altimetry data from 1993 to 2010, the analysis shows that the average of sea surface height anomaly varies, ranging from -15 cm to 15 cm. Spatially and zonally, there are three patterns that can be concidered as sea surface height anomaly characteristics: anomaly is higher in coastal areas than in open seas, anomaly is lower in coastal areas than in open seas and anomaly in coastal area is almost the same as in open seas. The first and second patterns occur in the south and north seas of Java Island. The third pattern occurs simultaneously in south and north seas of Java Island. Characteristics of temporal anomaly have a sinusoidal pattern in south and north seas of Java Island.
11
Benedek, G., G. Brusdeylins, C. Heimlich, L. Miglio, J. G. Skofronick, J. P. Toennies, and R. Vollmer. "Shifted surface-phonon anomaly in 2H-TaSe2." Physical Review Letters 60, no. 11 (March 14, 1988): 1037–40. http://dx.doi.org/10.1103/physrevlett.60.1037.
Повний текст джерела
12
Bush, Gary G., G. P. Rodrigue, and K. O. Legg. "Magnetic surface anomaly in high purity YIG." Journal of Applied Physics 57, no. 8 (April 15, 1985): 3704–5. http://dx.doi.org/10.1063/1.334996.
Повний текст джерела
13
Mahaux, C., and R. Sartor. "Fermi-surface anomaly for neutrons in yttrium." Physical Review C 36, no. 5 (November 1, 1987): 1777–84. http://dx.doi.org/10.1103/physrevc.36.1777.
Повний текст джерела
14
Aldén, M., H. L. Skriver, S. Mirbt, and B. Johansson. "Calculated surface-energy anomaly in the 3dmetals." Physical Review Letters 69, no. 15 (October 12, 1992): 2296–98. http://dx.doi.org/10.1103/physrevlett.69.2296.
Повний текст джерела
15
Lacy, Claud H., Marian L. Frueh, and Andrew E. Turner. "The surface-brightness anomaly in eclipsing binaries." Astronomical Journal 94 (October 1987): 1035. http://dx.doi.org/10.1086/114537.
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16
Hasibuan, Jamaludin, Asdiati Berutu, Halimahtun Sakdiah, and Rahmatsyah Rahmatsyah. "Studi Penentuan Anomali Situs Purbakala di Tapanuli Tengah Dengan Metode Geomagnetik." Wahana Fisika 2, no. 1 (June 20, 2017): 1. http://dx.doi.org/10.17509/wafi.v2i1.7040.
Повний текст джерелаАнотація:
Penelitian penentuan anomali magnetik situs arkeologi di Tapanuli Tengah dengan metode geomagnetik telah dilakukan untuk mengetahui adanya penampang anomali magnetik di lokasi Lobu Tua. Metode pengukuran Geomagnet menggunakan tipe PPM (Proton Precession Magnetometer) Elsec 770, pengambilan data dilakukan secara acak dengan jumlah titik yang diperoleh 51 titik pengukuran, pengolahan data menggunakan surfer 11 untuk mendapatkan peta kontur dan Mag2DC for windows. Hasil penelitian menunjukkan bahwa penyebaran struktur pelapis Lobu Tua menggunakan metode geomagnet menyebar secara vertikal dan horizontal. Anomali dengan metode geomagnetik memiliki nilai terendah - 122,34 nT dan nilai tertinggi adalah -100,34 nT, dan nilai suseptibilitas 0,77, 0,87, 0,91 dimana model anomali permukaan didominasi oleh batuan alluvium sesuai dengan Peta geologi.Research on the determination of anomaly archaeological site in Central Tapanuli by geomagnetic method has been done in order to know the magnetic anomaly cross section of Lobu Tua site. Geomagnet measurement method using PPM (Proton Precession Magnetometer) type Elsec 770, data retrieval is done randomly with number of point obtained 51 point measure, data processing using surfer 11 to get contour map and Mag2DC for windows. The result of the research shows that the dissemination of Lobu Tua's site coating structure using geomagnet method is spread vertically and horizontally. The anomaly with geomagnetic method has the lowest value - 122,34 nT and the highest value is -100,34 nT, and the susceptibility value 0,77, 0,87, 0.91 where the surface anomaly model is dominated by alluvium rocks according to the geological map.
17
Diedhiou, Arona, and Jean-Francçois Mahfouf. "Comparative influence of land and sea surfaces on the Sahelian drought: a numerical study." Annales Geophysicae 14, no. 1 (January 31, 1996): 115–30. http://dx.doi.org/10.1007/s00585-996-0115-6.
Повний текст джерелаАнотація:
Abstract. The aim of this work is to compare the relative impact of land and sea surface anomalies on Sahel rainfall and to describe the associated anomalies in the atmospheric general circulation. This sensitivity study was done with the Météo-France climate model: ARPEGE. The sensitivity to land surface conditions consists of changes in the management of water and heat exchanges by vegetation cover and bare soil. The sensitivity to ocean surfaces consists in forcing the lower boundary of the model with worldwide composite sea surface temperature (SST) anomalies obtained from the difference between 4 dry Sahel years and 4 wet Sahel years observed since 1970. For each case, the spatiotemporal variability of the simulated rainfall anomaly and changes in the modelled tropical easterly jet (TEJ) and African easterly jet (AEJ) are discussed. The global changes in land surface evaporation have caused a rainfall deficit over the Sahel and over the Guinea Coast. No significant changes in the simulated TEJ and an enhancement of the AEJ are found; at the surface, the energy budget and the hydrological cycle are substantially modified. On the other hand, SST anomalies induce a negative rainfall anomaly over the Sahel and a positive rainfall anomaly to the south of this area. The rainfall deficit due to those anomalies is consistent with previous diagnostic and sensitivity studies. The TEJ is weaker and the AEJ is stronger than in the reference. The composite impact of SST and land surfaces anomalies is also analyzed: the simulated rainfall anomaly is similar to the observed mean African drought patterns. This work suggests that large-scale variations of surface conditions may have a substantial influence on Sahel rainfall and shows the importance of land surface parameterization in climate change modelling. In addition, it points out the interest in accurately considering the land and sea surfaces conditions in sensitivity studies on Sahel rainfall.
18
Pavlakis, K. G., N. Hatzianastassiou, C. Matsoukas, A. Fotiadi, and I. Vardavas. "ENSO surface shortwave radiation forcing over the tropical Pacific." Atmospheric Chemistry and Physics 8, no. 18 (September 18, 2008): 5565–77. http://dx.doi.org/10.5194/acp-8-5565-2008.
Повний текст джерелаАнотація:
Abstract. We have studied the spatial and temporal variation of the downward shortwave radiation (DSR) at the surface of the Earth during ENSO events for a 21-year period over the tropical and subtropical Pacific Ocean (40° S–40° N, 90° E–75° W). The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database, reanalysis data from NCEP/NCAR for the key atmospheric and surface input parameters, and aerosol parameters from GADS (acronyms explained in main text). A clear anti-correlation was found between the downward shortwave radiation anomaly (DSR-A) time-series, in the region 7° S–5° N 160° E–160° W located west of the Niño-3.4 region, and the Niño-3.4 index time-series. In this region where the highest in absolute value DSR anomalies are observed, the mean DSR anomaly values range from −45 Wm−2 during El Niño episodes to +40 Wm−2 during La Niña events. Within the Niño-3.4 region no significant DSR anomalies are observed during the cold ENSO phase in contrast to the warm ENSO phase. A high correlation was also found over the western Pacific (10° S–5° N, 120–140° E), where the mean DSR anomaly values range from +20 Wm−2 to −20 Wm−2 during El Niño and La Niña episodes, respectively. There is also convincing evidence that the time series of the mean downward shortwave radiation anomaly in the off-equatorial western Pacific region 7–15° N 150–170° E, precedes the Niño-3.4 index time-series by about 7 months and the pattern of this anomaly is indicative of ENSO operating through the mechanism of the western Pacific oscillator. Thus, the downward shortwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to assess whether or not El Niño or La Niña conditions prevail.
19
Li, Hai Xia, Hai Long Yu, and Xiao Ling Zhang. "Application Effect Analysis of Magnetic Gradients Data Continuation from Undulate Surface to Plane." Advanced Materials Research 779-780 (September 2013): 643–46. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.643.
Повний текст джерелаАнотація:
Application effect of magnetic gradients data continuation from undulate surface to plane has been analyzed by model test. The gradient data of before and after the processing was used for the analytic signal and the Euler deconvolution method calculation respectively, comparing the calculated results show that the maxima of analytic signal calculated by gradients anomaly on undulate surface deviate obviously from the center location of the prism magnetic source, and the position of prism boundaries are not clear. However, the analytic signal calculated by gradients anomaly after continuation from undulate surface to plane can be successfully used to estimate the center and boundaries position of prism. The solutions of Euler deconvolution method calculated by gradients anomaly on undulate surface are dispersive, the solutions calculated by gradients anomaly after continuation from undulate surface to plane are relatively clustering, and can outline clearly the positions of prism corners. The results demonstrate that continuation from undulate surface to plane processing of gradients anomaly can improve the application effect of analytic signal and Euler deconvolution technique.
20
Pavlakis, K. G., N. Hatzianastassiou, C. Matsoukas, A. Fotiadi, and I. Vardavas. "ENSO surface shortwave radiation forcing over the tropical Pacific." Atmospheric Chemistry and Physics Discussions 8, no. 2 (April 7, 2008): 6697–728. http://dx.doi.org/10.5194/acpd-8-6697-2008.
Повний текст джерелаАнотація:
Abstract. We have studied the spatial and temporal variation of the downward shortwave radiation (DSR) at the surface of the Earth during ENSO events for a 21-year period over the tropical and subtropical Pacific Ocean (40° S–40° N, 90° E–75° W). The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database, reanalysis data from NCEP/NCAR for the key atmospheric and surface input parameters, and aerosol parameters from GADS (acronyms explained in main text). A clear anti-correlation was found between the downward shortwave radiation anomaly (DSR-A) time-series, in the region 7° S–5° N 160° E-160° W located west of the Niño-3.4 region, and the Niño-3.4 index time-series. In this region where the highest in absolute value DSR anomalies are observed, the mean DSR anomaly values range from −45 Wm−2 during El Niño episodes to +40 Wm−2 during La Niña events. Within the Niño-3.4 region no significant DSR anomalies are observed during the cold ENSO phase in contrast to the warm ENSO phase. A high correlation was also found over the western Pacific (10° S–5° N, 120–140° E), where the mean DSR anomaly values range from +20 Wm−2 to −20 Wm−2 during El Niño and La Niña episodes, respectively. There is also convincing evidence that the time series of the mean downward shortwave radiation anomaly in the north subtropical Pacific region 7–15° N 150–170° E, precedes the Niño-3.4 index time-series by about 7 months. Thus, the downward shortwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to assess whether or not El Niño or La Niña conditions prevail.
21
Rasul, Azad, and Luqman W. Omar. "Land Surface Temperature Anomalies Detection for the Strong Earthquakes in 2018." ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY 8, no. 2 (September 1, 2020): 15–21. http://dx.doi.org/10.14500/aro.10591.
Повний текст джерелаАнотація:
Earthquake every year leads to human and material losses and unpredictability of it by now makes this natural disaster worsen. The objective of the current study was to determine the anomalies in land surface temperature (LST) in areas affected by earthquakes. In this research, three earthquakes (M >6) were studied. Moderate Resolution Imaging Spectroradiometer Aqua and Terra day and night LST data used from 2003 to 2018. The interquartile range (IQR) and mean ± 2σ methods utilized to select anomalies. As a result, based on the IQR method, no prior and after anomaly detected in selected cases and data. Based on mean ± 2σ, usually positive anomaly occurred during daytime. However, negative (or positive) anomaly occurred during the nighttime before the Mexico and Bolivia earthquakes. During 10 days after the earthquake, sometimes a negative anomaly detected.
22
Shamsad, M., MA Farukh, MJR Chowdhury, and SC Basak. "Sea Surface Temperature Anomaly in the Bay of Bengal in 2010." Journal of Environmental Science and Natural Resources 5, no. 2 (April 29, 2013): 77–80. http://dx.doi.org/10.3329/jesnr.v5i2.14797.
Повний текст джерелаАнотація:
Bangladesh is one of the most disaster prone countries in the world and is a victim of frequent natural calamities like tropical cyclones, tornadoes, floods, storm surges and droughts. Sea surface temperature (SST) plays a vital role in determining ocean-atmosphere interaction. In this study we focused on understanding the behavior of SST anomaly prevailed in the region of Bay of Bengal mainly to assume the surface temperature signature for cyclone occurrence. For this study, the observed SST anomaly data were derived from NOAA Coast-watch using a combination of global and regional algorithms. The SST anomaly maps were produced using SAGA-GIS software where the SST lines were fixed at the mean of 30 years data. The AVHRR SST was compared with the climatological SST for the region of Bay of Bengal in 2010. The monthly SST anomaly for 2010 showed average departure of 0.7°C for all the months except June and October. It was found that the anomaly increases about 2°C at the end of September, and in October the basin bears no significant anomaly.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14797 J. Environ. Sci. & Natural Resources, 5(2): 77-80 2012
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Sattar, Shahram, Songnian Li, and Michael Chapman. "Road Surface Monitoring Using Smartphone Sensors: A Review." Sensors 18, no. 11 (November 9, 2018): 3845. http://dx.doi.org/10.3390/s18113845.
Повний текст джерелаАнотація:
Road surface monitoring is a key factor to providing smooth and safe road infrastructure to road users. The key to road surface condition monitoring is to detect road surface anomalies, such as potholes, cracks, and bumps, which affect driving comfort and on-road safety. Road surface anomaly detection is a widely studied problem. Recently, smartphone-based sensing has become increasingly popular with the increased amount of available embedded smartphone sensors. Using smartphones to detect road surface anomalies could change the way government agencies monitor and plan for road maintenance. However, current smartphone sensors operate at a low frequency, and undersampled sensor signals cause low detection accuracy. In this study, current approaches for using smartphones for road surface anomaly detection are reviewed and compared. In addition, further opportunities for research using smartphones in road surface anomaly detection are highlighted.
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Dacre, Helen F., Simon A. Josey, and Alan L. M. Grant. "Extratropical-cyclone-induced sea surface temperature anomalies in the 2013–2014 winter." Weather and Climate Dynamics 1, no. 1 (February 4, 2020): 27–44. http://dx.doi.org/10.5194/wcd-1-27-2020.
Повний текст джерелаАнотація:
Abstract. The 2013–2014 winter averaged sea surface temperature (SST) was anomalously cool in the mid-North Atlantic region. This season was also unusually stormy, with extratropical cyclones passing over the mid-North Atlantic every 3 d. However, the processes by which cyclones contribute towards seasonal SST anomalies are not fully quantified. In this paper a cyclone identification and tracking method is combined with European Centre for Medium-Range Weather Forecasts (ECMWF) atmosphere and ocean reanalysis fields to calculate cyclone-relative net surface heat flux anomalies and resulting SST changes. Anomalously large negative heat flux is located behind the cyclones' cold front, resulting in anomalous cooling up to 0.2 K d−1 when the cyclones are at maximum intensity. This extratropical-cyclone-induced “cold wake” extends along the cyclones' cold front but is small compared to climatological variability in the SSTs. To investigate the potential cumulative effect of the passage of multiple cyclone-induced SST cooling in the same location, we calculate Earth-relative net surface heat flux anomalies and resulting SST changes for the 2013–2014 winter period. Anomalously large winter averaged negative heat flux occurs in a zonally orientated band extending across the North Atlantic between 40 and 60∘ N. The 2013–2014 winter SST cooling anomaly associated with air–sea interactions (ASIs; anomalous heat flux, mixed layer depth and entrainment at the base of the ocean mixed layer) is estimated to be −0.67 K in the mid-North Atlantic (68 % of the total cooling anomaly). The role of cyclones is estimated using a cyclone-masking technique which encompasses each cyclone centre and its cold wake. The environmental flow anomaly in 2013–2014 sets the overall tripole pattern of heat flux anomalies over the North Atlantic. However, the presence of cyclones doubles the magnitude of the negative heat flux anomaly in the mid-North Atlantic. Similarly, the environmental flow anomaly determines the location of the SST cooling anomaly, but the presence of cyclones enhances the SST cooling anomaly. Thus air–sea interactions play a major part in determining the extreme 2013–2014 winter season SST cooling anomaly. The environmental flow anomaly determines where anomalous heat flux and associated SST changes occur, and the presence of cyclones influences the magnitude of those anomalies.
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Chakraborty, Subrata, and S. K. Bhattacharya. "Oxygen isotopic anomaly in surface induced ozone dissociation." Chemical Physics Letters 369, no. 5-6 (February 2003): 662–67. http://dx.doi.org/10.1016/s0009-2614(03)00018-6.
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Tsai, Du-Ming, and Po-Hao Jen. "Autoencoder-based anomaly detection for surface defect inspection." Advanced Engineering Informatics 48 (April 2021): 101272. http://dx.doi.org/10.1016/j.aei.2021.101272.
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Müller, J. E., M. Wuttig, and H. Ibach. "Adsorbate-Induced Surface Stress: Phonon Anomaly and Reconstruction on Ni(001) Surfaces." Physical Review Letters 56, no. 15 (April 14, 1986): 1583–86. http://dx.doi.org/10.1103/physrevlett.56.1583.
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Beron-Vera, Francisco J., María J. Olascoaga, and Gustavo J. Goni. "Surface Ocean Mixing Inferred from Different Multisatellite Altimetry Measurements." Journal of Physical Oceanography 40, no. 11 (November 1, 2010): 2466–80. http://dx.doi.org/10.1175/2010jpo4458.1.
Повний текст джерелаАнотація:
Abstract Two sea surface height (SSH) anomaly fields distributed by Archiving, Validation, and Interpretation of Satellite Oceanographic (AVISO) Altimetry are evaluated in terms of the effects that they produce on mixing. One SSH anomaly field, tagged REF, is constructed using measurements made by two satellite altimeters; the other SSH anomaly field, tagged UPD, is constructed using measurements made by up to four satellite altimeters. Advection is supplied by surface geostrophic currents derived from the total SSH fields resulting from the addition of these SSH anomaly fields to a mean SSH field. Emphasis is placed on the extraction from the currents of Lagrangian coherent structures (LCSs), which, acting as skeletons for patterns formed by passively advected tracers, entirely control mixing. The diagnostic tool employed to detect LCSs is provided by the computation of finite-time Lyapunov exponents. It is found that currents inferred using UPD SSH anomalies support mixing with characteristics similar to those of mixing produced by currents inferred using REF SSH anomalies. This result mainly follows from the fact that, being more easily characterized as chaotic than turbulent, mixing as sustained by currents derived using UPD SSH anomalies is quite insensitive to spatiotemporal truncations of the advection field.
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Mochizuki, Takashi, and Hideji Kida. "Seasonality of Decadal Sea Surface Temperature Anomalies in the Northwestern Pacific." Journal of Climate 19, no. 12 (June 15, 2006): 2953–68. http://dx.doi.org/10.1175/jcli3807.1.
Повний текст джерелаАнотація:
Abstract The seasonality of the decadal sea surface temperature (SST) anomalies and the related physical processes in the northwestern Pacific were investigated using a three-dimensional bulk mixed layer model. In the Kuroshio–Oyashio Extension (KOE) region, the strongest decadal SST anomaly was observed during December–February, while that of the central North Pacific occurred during February–April. From an examination of the seasonal heat budget of the ocean mixed layer, it was revealed that the seasonal-scale enhancement of the decadal SST anomaly in the KOE region was controlled by horizontal Ekman temperature transport in early winter and by vertical entrainment in autumn. The temperature transport by the geostrophic current made only a slight contribution to the seasonal variation of the decadal SST anomaly, despite controlling the upper-ocean thermal conditions on decadal time scales through the slow Rossby wave adjustment to the wind stress curl. When averaging over the entire KOE region, the contribution from the net sea surface heat flux was also no longer significantly detected. By examining the horizontal distributions of the local thermal damping rate, however, it was concluded that the wintertime decadal SST anomaly in the eastern KOE region was rather damped by the net sea surface heat flux. It was due to the fact that the anomalous local thermal damping of the SST anomaly resulting from the vertical entrainment in autumn was considerably strong enough to suppress the anomalous local atmospheric thermal forcing that acted to enhance the decadal SST anomaly.
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Lambert, F. Hugo, Mark J. Webb, and Manoj M. Joshi. "The Relationship between Land–Ocean Surface Temperature Contrast and Radiative Forcing." Journal of Climate 24, no. 13 (July 1, 2011): 3239–56. http://dx.doi.org/10.1175/2011jcli3893.1.
Повний текст джерелаАнотація:
Abstract Previous work has demonstrated that observed and modeled climates show a near-time-invariant ratio of mean land to mean ocean surface temperature change under transient and equilibrium global warming. This study confirms this in a range of atmospheric models coupled to perturbed sea surface temperatures (SSTs), slab (thermodynamics only) oceans, and a fully coupled ocean. Away from equilibrium, it is found that the atmospheric processes that maintain the ratio cause a land-to-ocean heat transport anomaly that can be approximated using a two-box energy balance model. When climate is forced by increasing atmospheric CO2 concentration, the heat transport anomaly moves heat from land to ocean, constraining the land to warm in step with the ocean surface, despite the small heat capacity of the land. The heat transport anomaly is strongly related to the top-of-atmosphere radiative flux imbalance, and hence it tends to a small value as equilibrium is approached. In contrast, when climate is forced by prescribing changes in SSTs, the heat transport anomaly replaces “missing” radiative forcing over land by moving heat from ocean to land, warming the land surface. The heat transport anomaly remains substantial in steady state. These results are consistent with earlier studies that found that both land and ocean surface temperature changes may be approximated as local responses to global mean radiative forcing. The modeled heat transport anomaly has large impacts on surface heat fluxes but small impacts on precipitation, circulation, and cloud radiative forcing compared with the impacts of surface temperature change. No substantial nonlinearities are found in these atmospheric variables when the effects of forcing and surface temperature change are added.
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Clark, Joseph P., and Steven B. Feldstein. "What Drives the North Atlantic Oscillation’s Temperature Anomaly Pattern? Part I: The Growth and Decay of the Surface Air Temperature Anomalies." Journal of the Atmospheric Sciences 77, no. 1 (December 16, 2019): 185–98. http://dx.doi.org/10.1175/jas-d-19-0027.1.
Повний текст джерелаАнотація:
Abstract Composite analysis is used to examine the physical processes that drive the growth and decay of the surface air temperature anomaly pattern associated with the North Atlantic Oscillation (NAO). Using the thermodynamic energy equation that the European Centre for Medium-Range Weather Forecasts implements in their reanalysis model, we show that advection of the climatological temperature field by the anomalous wind drives the surface air temperature anomaly pattern for both NAO phases. Diabatic processes exist in strong opposition to this temperature advection and eventually cause the surface air temperature anomalies to return to their climatological values. Specifically, over Greenland, Europe, and the United States, longwave heating/cooling opposes horizontal temperature advection while over northern Africa vertical mixing opposes horizontal temperature advection. Despite the pronounced spatial correspondence between the skin temperature and surface air temperature anomaly patterns, the physical processes that drive these two temperature anomalies associated with the NAO are found to be distinct. The skin temperature anomaly pattern is driven by downward longwave radiation whereas stated above, the surface air temperature anomaly pattern is driven by horizontal temperature advection. This implies that the surface energy budget, although a useful diagnostic tool for understanding skin temperature changes, should not be used to understand surface air temperature changes.
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Su, Hui, J. David Neelin, and Joyce E. Meyerson. "Sensitivity of Tropical Tropospheric Temperature to Sea Surface Temperature Forcing*." Journal of Climate 16, no. 9 (May 1, 2003): 1283–301. http://dx.doi.org/10.1175/1520-0442-16.9.1283.
Повний текст джерелаАнотація:
Abstract During El Niño, there are substantial tropospheric temperature anomalies across the entire tropical belt associated with the warming of sea surface temperatures (SSTs) in the central and eastern Pacific. The quasi-equilibrium tropical circulation model (QTCM) is used to investigate the mechanisms for tropical tropospheric temperature response to SST forcing. In both observations and model simulations, the tropical averaged tropospheric temperature anomaly 〈T̂′〉 is approximately linear with the tropical mean SST anomaly 〈T′s〉 for observed SST forcing. Regional SST anomaly experiments are used to estimate regional sensitivity measures and quantify the degree of nonlinearity. For instance, SST anomalies of 3°C in the central Pacific would give a nonlinear 〈T̂′〉 response about 15% greater than a linear fit to small SST anomaly experiments would predict, but for the maximum observed SST anomaly in this region the response differs by only 5% from linearity. Nonlinearity in 〈T̂′〉 response is modest even when local precipitation response is highly nonlinear. While temperature anomalies have large spatial scales, the main precipitation anomaly tends to be local to the SST anomaly regions. The tropical averaged precipitation anomalies 〈P′〉 do not necessarily have a simple relation to tropical averaged tropospheric temperature anomalies or SST forcing. The approximate linearity of the 〈T̂′〉 response is due to two factors: 1) the strong nonlinearities that occur locally tend to be associated with the transport terms, which become small in the large-area average; and 2) the dependence on temperature of the top-of-atmosphere and surface fluxes has only weak nonlinearity over the range of 〈T̂′〉 variations. Analytical approximations to the QTCM suggest that the direct impact of climatological SST, via flux terms, contributes modestly to regional variations in the sensitivity α of 〈T̂′〉 to 〈T′s〉. Wind speed has a fairly strong effect on α but tends to oppose the direct effect of SST since cold SST regions often have stronger climatological wind, which would yield larger slopes. A substantial contribution to regional variation in α comes from the different reaction of moisture to SST anomalies in precipitating and nonprecipitating regions. Although regions over climatologically warm water have a slightly higher sensitivity, subregions of El Niño SST anomalies even in the colder eastern Pacific contribute substantially to tropospheric temperature anomalies.
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MAZZEO, RAFE, and JULIE ROWLETT. "A heat trace anomaly on polygons." Mathematical Proceedings of the Cambridge Philosophical Society 159, no. 2 (June 19, 2015): 303–19. http://dx.doi.org/10.1017/s0305004115000365.
Повний текст джерелаАнотація:
AbstractLet Ω0be a polygon in$\mathbb{R}$2, or more generally a compact surface with piecewise smooth boundary and corners. Suppose that Ωεis a family of surfaces with${\mathcal C}$∞boundary which converges to Ω0smoothly away from the corners, and in a precise way at the vertices to be described in the paper. Fedosov [6], Kac [8] and McKean–Singer [13] recognised that certain heat trace coefficients, in particular the coefficient oft0, are not continuous as ε ↘ 0. We describe this anomaly using renormalized heat invariants of an auxiliary smooth domainZwhich models the corner formation. The result applies to both Dirichlet and Neumann boundary conditions. We also include a discussion of what one might expect in higher dimensions.
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Çakır, Özcan, and Nart Coşkun. "Dispersion of Rayleigh Surface Waves and Electrical Resistivities Utilized to Invert Near Surface Structural Heterogeneities." Journal of Human, Earth, and Future 3, no. 1 (March 1, 2022): 1–16. http://dx.doi.org/10.28991/hef-2022-03-01-01.
Повний текст джерелаАнотація:
The single-station Rayleigh surface wave group velocities and electrical resistivities are two data sets that we cooperatively employ to image the near surface (< 40-m) anomaly structures. We numerically simulate the corresponding field measurements where the anomaly structures are assumed to have two-dimensional (2D) variations. The surface waves are represented by fundamental mode dispersion curves, and the electrical resistivities are assumed to be measured by using direct currents. We consider two types of anomaly structures, i.e., cavity and ore body. These two heterogeneities are easily distinguished from the surrounding geomaterial by their distinct physical properties. The cavity is characterized by low seismic velocity and high electrical resistivity, while the ore body is characterized by high seismic velocity and low electrical resistivity. The Rayleigh surface wave data is assumed to be collected throughout the classical common-shot gather. Multiple electrodes, multiple core cables, and multiple arrays are assumed to be used in the electrical survey. Both surface wave group velocities and electrical resistivities are shown to properly invert the anomalous structures in the subsurface. The surface wave group velocities have good horizontal resolution, while the corresponding vertical resolution is somewhat lower. The electrical resistivities have good resolution for shallow structures, but the resolution becomes somewhat reduced with increasing depth. Doi: 10.28991/HEF-2022-03-01-01 Full Text: PDF
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Zhang, Rong, and Geoffrey K. Vallis. "Impact of Great Salinity Anomalies on the Low-Frequency Variability of the North Atlantic Climate." Journal of Climate 19, no. 3 (February 1, 2006): 470–82. http://dx.doi.org/10.1175/jcli3623.1.
Повний текст джерелаАнотація:
Abstract In this paper, it is shown that coherent large-scale low-frequency variabilities in the North Atlantic Ocean—that is, the variations of thermohaline circulation, deep western boundary current, northern recirculation gyre, and Gulf Stream path—are associated with high-latitude oceanic Great Salinity Anomaly events. In particular, a dipolar sea surface temperature anomaly (warming off the U.S. east coast and cooling south of Greenland) can be triggered by the Great Salinity Anomaly events several years in advance, thus providing a degree of long-term predictability to the system. Diagnosed phase relationships among an observed proxy for Great Salinity Anomaly events, the Labrador Sea sea surface temperature anomaly, and the North Atlantic Oscillation are also discussed.
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DATTA, RK. "Temperature anomaly over Antarctica and monsoon activity." MAUSAM 40, no. 1 (April 28, 2022): 111–16. http://dx.doi.org/10.54302/mausam.v40i1.1971.
Повний текст джерелаАнотація:
Antarctica covers a significant portion of the southern hemisphere where surface temperature can be as low as -70°C compared to the surface temperature of 28°C over equatorial region. In this study a possible linkage between anomalies of surface temperature over Antarctica and the performance of monsoon has been examined.
It is observed that the preceding January surface temperature anomaly pattern over Antarctica has an association with the performance of the following monsoon. Drought years are preceded by predominantly warm anomalies over Antarctica and good monsoon years are preceded by equally marked cold anomalies.
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Phillips, Thomas J. "Reproducibility of Seasonal Land Surface Climate." Journal of Hydrometeorology 7, no. 1 (February 1, 2006): 114–36. http://dx.doi.org/10.1175/jhm453.1.
Повний текст джерелаАнотація:
Abstract In this study, the sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the “reproducibility” of continental climate for different initial conditions, spatiotemporal correlations are computed across paired realizations of 11 model land surface variables in which the seasonal cycle is either included or excluded—the former case being pertinent to climate simulation and the latter to seasonal prediction. It is found that the land surface variables that include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Niño–Southern Oscillation. However, the overall degree of reproducibility depends on the particular land surface anomaly considered. It is also shown that the predictability of a land surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability metrics. Implications of these results for climate model intercomparison projects and for operational forecasts of seasonal continental climate also are elaborated.
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Fang, Chen, and Liang Fu. "New classes of topological crystalline insulators having surface rotation anomaly." Science Advances 5, no. 12 (December 2019): eaat2374. http://dx.doi.org/10.1126/sciadv.aat2374.
Повний текст джерелаАнотація:
We discover new types of quantum anomalies in two-dimensional systems with time-reversal symmetry (T) and discrete rotation symmetry with order of n = 2, 4, and 6 (Cn). The new anomalous states have n flavors of massless Dirac fermions protected by T and Cn, whereas any two-dimensional lattices having the two symmetries must have a multiple of 4, 8, and 12 Dirac cones for n = 2, 4, and 6, respectively. We show that these anomalous states are physically realized on the surface of new classes of topological crystalline insulators, normal to the rotation axis. Moreover, these topological crystalline insulators support n gapless one-dimensional helical mode on the otherwise fully gapped side surface, connecting the anomalous two-dimensional states on the top and bottom surfaces. The presence of these helical modes enables a new quantum device made from a topological crystalline insulator nanorod, a “helical nanorod,” which has a quantized longitudinal conductance of ne2/h.
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Prasetio, Rasi, Neneng Laksminingpuri, and Evarista Ristin Pujiindiyati. "Konsentrasi Radon-222 dalam Gas Tanah untuk Deteksi Distribusi Permeabilitas di Daerah Panas Bumi Tampomas, Jawa Barat." EKSPLORIUM 41, no. 1 (May 30, 2020): 53. http://dx.doi.org/10.17146/eksplorium.2020.41.1.5642.
Повний текст джерелаАнотація:
ABSTRAK Daerah upflow dalam sistem panas bumi merupakan daerah dengan permeabilitas yang tinggi sebagai lintasan naiknya fluida panas bumi ke permukaan, yang umumnya ditandai dengan adanya fumarol di permukaan. Gunung Tampomas, Jawa Barat, merupakan salah satu lokasi potensi panas bumi yang memiliki manifestasi berupa mata air panas, namun tidak memiliki fumarol atau steam vent. Zona permeabel atau upflow sulit untuk diidentifikasi. Isotop 222Rn merupakan isotop geogenik yang konsentrasinya di dalam gas tanah dapat menunjukkan permeabilitas, baik permeabilitas primer maupun sekunder (struktur). Serangkaian pengukuran 222Rn dalam gas tanah telah dilakukan pada 56 titik di sekitar Gunung Tampomas untuk melihat anomali kandungan 222Rn dengan menggunakan metode statistik, serta relasinya antara daerah dengan permeabilitas tinggi dengan struktur geologi dan manifestasi panas bumi. Hasil pengukuran dan evaluasi statistik menunjukkan bahwa konsentrasi 222Rn terbagi menjadi konsentrasi rendah (latar), konsentrasi tinggi, dan anomali. Nilai latar berada di 16 lokasi berada di bawah 825 Bq/m3, sementara konsentrasi tinggi di 32 lokasi antara 825–7688 Bq/m3 dan anomali di 8 lokasi di atas 7688 Bq/m3. Sebagian besar lokasi dengan konsentrasi 222Rn tinggi dan anomali letaknya tidak berdekatan dengan kelurusan struktur, Seluruh pengukuran yang berdekatan dengan mata air panas memiliki konsentrasi 222Rn tinggi dan anomali. Mata air panas Ciseupan merupakan pengecualian yang mengindikasikan air panas tersebut keluar secara lateral (outflow). Selain itu, tidak ada indikasi korelasi antara konsentrasi 222Rn dengan elevasi lokasi pengukuran. Proses perpindahan 222Rn dari reservoir ke permukaan diperkirakan melalui mekanisme gas pembawa yang berasal dari reservoir panas bumi melalui zona permeabel.ABSTRACT Upflow zone in the geothermal system is a zone with high permeability that serves as a path for geothermal fluid to ascend to the surface, which usually marked with fumarole at the surface. Mount Tampomas, West Java, is a potential geothermal site with some thermal manifestation in the form of hot springs, but no fumarole or steam vent exists. The up-flow or the permeable zone is difficult to identify. 222Rn isotope is a radiogenic isotope that its concentration in soil gas can infer primary permeability as well as secondary permeability (structure). Series of 222Rn measurement in soil gas has been performed from 56 sampling positions around Mount Tampomas to evaluate 222Rn anomaly by a statistical method and its relation with high permeability area, geological structure, and geothermal manifestation. The measurement and statistical evaluation results show that 222Rn concentration clustered into low (background), high, and anomaly concentration. The background values in 16 places are below 825 Bq/m3, while a high level in 32 areas between 825–7688 Bq/m3 and anomaly in 8 places above 7688 Bq/m3. Most of the locations with high and anomaly 222Rn concentrations did not locate near a structure lineament. All measurements near hot springs have a high 222Rn and anomaly. Ciseupan hot spring is an exception which may indicate that the hot spring is discharged laterally (outflow). Furthermore, there is no indication of a correlation between 222Rn with the elevation of the measurement location. The process of 222Rn transfer from the reservoir to the surface is considered by the geothermal reservoir's gas carrier mechanism through permeable zones.
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Liu, Gaokai, Ning Yang, and Lei Guo. "An Attention-Based Network for Textured Surface Anomaly Detection." Applied Sciences 10, no. 18 (September 8, 2020): 6215. http://dx.doi.org/10.3390/app10186215.
Повний текст джерелаАнотація:
Textured surface anomaly detection is a significant task in industrial scenarios. In order to further improve the detection performance, we proposed a novel two-stage approach with an attention mechanism. Firstly, in the segmentation network, the feature extraction and anomaly attention modules are designed to capture the detail information as much as possible and focus on the anomalies, respectively. To strike dynamic balances between these two parts, an adaptive scheme where learnable parameters are gradually optimized is introduced. Subsequently, the weights of the segmentation network are frozen, and the outputs are fed into the classification network, which is trained independently in this stage. Finally, we evaluate the proposed approach on DAGM 2007 dataset which consists of diverse textured surfaces with weakly-labeled anomalies, and the experiments demonstrate that our method can achieve 100% detection rates in terms of TPR (True Positive Rate) and TNR (True Negative Rate).
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Fatland, Dennis R., Craig S. Lingle, and Martin Truffer. "A surface motion survey of Black Rapids Glacier, Alaska, U.S.A." Annals of Glaciology 36 (2003): 29–36. http://dx.doi.org/10.3189/172756403781816095.
Повний текст джерелаАнотація:
AbstractWe describe a derivation of surface velocities and associated errors for Black Rapids Glacier, Alaska, U.S.A., using single-orbital-path synthetic aperture radar interferometry (InSAR). The technique described is adapted to small temperate glaciers with complex flow patterns. We also describe a motion anomaly, apparent in the InSAR phase signal, that persisted on Black Rapids Glacier for at least 78 days during winter 1991/92 and recurred in 1996. This anomaly is interpreted using a basal hydrology hypothesis in which a hydraulic head is maintained at the glacier bed at close to the overburden pressure. This permits a cumulative influx of 1.6 × 106 m3 of water under the glacier, a sort of shallow subglacial lake, that migrates downstream at an average rate of 30 m d− 1 over 78 days. The motion anomaly is speculated to be an unsuccessful bid for surge initiation.
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Stolz, Bernadette J., Jared Tanner, Heather A. Harrington, and Vidit Nanda. "Geometric anomaly detection in data." Proceedings of the National Academy of Sciences 117, no. 33 (August 3, 2020): 19664–69. http://dx.doi.org/10.1073/pnas.2001741117.
Повний текст джерелаАнотація:
The quest for low-dimensional models which approximate high-dimensional data is pervasive across the physical, natural, and social sciences. The dominant paradigm underlying most standard modeling techniques assumes that the data are concentrated near a single unknown manifold of relatively small intrinsic dimension. Here, we present a systematic framework for detecting interfaces and related anomalies in data which may fail to satisfy the manifold hypothesis. By computing the local topology of small regions around each data point, we are able to partition a given dataset into disjoint classes, each of which can be individually approximated by a single manifold. Since these manifolds may have different intrinsic dimensions, local topology discovers singular regions in data even when none of the points have been sampled precisely from the singularities. We showcase this method by identifying the intersection of two surfaces in the 24-dimensional space of cyclo-octane conformations and by locating all of the self-intersections of a Henneberg minimal surface immersed in 3-dimensional space. Due to the local nature of the topological computations, the algorithmic burden of performing such data stratification is readily distributable across several processors.
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Hsu, Huang-Hsiung, and Ming-Ying Lee. "Topographic Effects on the Eastward Propagation and Initiation of the Madden–Julian Oscillation." Journal of Climate 18, no. 6 (March 15, 2005): 795–809. http://dx.doi.org/10.1175/jcli-3292.1.
Повний текст джерелаАнотація:
Abstract This study investigates the relationship between deep convection (and heating anomaly) in the Madden–Julian oscillation (MJO) and the tropical topography. The eastward propagation of the deep heating anomalies is confined to two regions: the Indian Ocean and the western Pacific warm pool. Superimposed on the eastward propagation is a series of quasi-stationary deep heating anomalies that occur sequentially and discretely downstream in a leapfrog manner in the central Indian Ocean, the Maritime Continent, tropical South America, and tropical Africa. The deep heating anomaly, usually preceded by near-surface moisture convergence and shallow heating anomalies, tends to occur on the windward side of the tropical topography in these regions (except the central Indian Ocean) under the prevailing surface easterly anomaly of the MJO. It is suggested that the lifting and frictional effects of the tropical topography and landmass induce the near-surface moisture convergence anomaly, which in turn triggers the deep heating anomaly. Subsequently, the old heating anomaly located to the west of the tropical topography weakens and the new heating anomaly east of the topography develops because of the eastward shift in the major moisture convergence center to the east of the mountains. Therefore, the deep heating anomaly shifts eastward from one region to another. The equatorial Kelvin wave, which is forced by the tropical heating anomaly and propagates quickly across the ocean basins in the lower troposphere, plays an important role by helping to strengthen the easterly anomaly and lowering the surface pressure. This process is proposed to further our understanding of the shift in the deep convection from the Indian Ocean to the western Pacific, the reappearance of the deep convection in tropical South America, and the initiation of the MJO in the western Indian Ocean. It is suggested that the fast eastward propagation and the slow development of quasi-stationary convection together determine the quasi-periodicity of the MJO.
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Lu, X., Q. Y. Meng, X. F. Gu, X. D. Zhang, P. Xiong, W. Y. Ma, and T. Xie. "Study on multi-parameters of thermal infrared remote sensing anomalies of the Yushu earthquake." Natural Hazards and Earth System Sciences Discussions 2, no. 6 (June 24, 2014): 4439–62. http://dx.doi.org/10.5194/nhessd-2-4439-2014.
Повний текст джерелаАнотація:
Abstract. Different temporal and special multi-parameters of infrared remote sensing anomalies of the Yushu earthquake, including the Outgoing Longwave Radiation (OLR), the Land Surface Temperature (LST) and surface temperature from the National Center for Environmental Prediction (NCEP) were studied in this paper. All results confirmed previous observation of thermal anomalies in seismic region prior to this earthquake. Compared to the multi-parameter anomalies, the underground water temperature anomaly appeared first and lasted for the longest time; OLR anomalies reflected the radiation characteristics of the land surface medium as the first infrared parametric anomaly; TBB anomalies appearing later than OLR are abnormal because the results were converted by calculating the radiation value of the underlying surface; the third thermal anomaly was LST. NCEP temperature reflected the average atmosphere temperature with a certain vertical thickness, therefore it was the latest anomaly. The anomalies of OLR, TBB and LST lasted for a similar time length and were nearly located in the south or southwest of the epicenter.
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Hidayat, Hidayat, Marjiyono Marjiyono, Zulilmatul S. Praromadani, Januar H.Setiawan, G. M. Lucki Junursyah, Subagio Subagio, Ahmad Setiawan, and Andrian Ibrahim. "Delineation of Banyumas Sub-Basins using Gravity Anomaly Based on Trend Surface Analysis Equation." Jurnal Geologi dan Sumberdaya Mineral 22, no. 4 (December 16, 2021): 231. http://dx.doi.org/10.33332/jgsm.geologi.v22i4.651.
Повний текст джерелаАнотація:
A study using gravity methods in the Banyumas Basin, located in the southern part of Central Java, Indonesia had been conducted to generate a map for regional geological features in sub-volcanic basin related to petroleum system. This study used the first and second-order of Trend Surface Analysis (TSA) to separate gravity anomaly into regional and residual components. Matrix inversion is applied to obtain constants values for both the first and second-order of TSA. To interpret geological features related to oil and gas study, residual components are used for gravity anomaly. Residual anomaly is also compared for both first and second order of TSA with a regional geological map to validate the result. Residual anomaly from the second order of TSA showed a very comparable result to geological features, as shown in the regional geological map, compared to those of the first order of TSA. These results also showed a strong contrast of some important geological features such as the Gabon-Nusakambangan Formation outcrop, Karangbolong outcrop, and the eastern part of the south Serayu mountain arc. This study also displayed two potential subbasins i.e Citanduy and Majenang sub-Basin that might be a possible setting in which source rocks of the Banyumas Basin were deposited. From this study, it can be concluded that TSA showed a reliable result of separating gravity anomaly data set into regional and residual components.Keywords: Gravity anomaly, Banyumas Basin, petroleum system, trend surface analysis (TSA).
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Yang, Wang, and Huang. "Intercomparison of the Surface Energy Partitioning in CMIP5 Simulations." Atmosphere 10, no. 10 (October 4, 2019): 602. http://dx.doi.org/10.3390/atmos10100602.
Повний текст джерелаАнотація:
The warming climate significantly modifies the global water cycle. Global evapotranspiration has increased over the past decades, yet climate models agree on the drying trend of land surface. In this study, we conducted an intercomparison analysis of the surface energy partitioning across Coupled Model Intercomparison Phase 5 (CMIP5) simulations and evaluated its behaviour with surface temperature and soil moisture anomalies, against the theoretically derived thermodynamic formula. Different responses over land and sea surfaces to elevated greenhouse gas emissions were found. Under the Representative Concentration Pathway of +8.5 W m−2 (RCP8.5) warming scenario, the multi-model mean relative efficiency anomaly from CMIP5 simulations is 3.83 and −0.12 over global sea and land, respectively. The significant anomaly over sea was captured by the thermodynamic solution based on the principle of maximum entropy production, with a mean relative error of 14.6%. The declining trend over land was also reproduced, but an accurate prediction of its small anomaly will require the inclusions of complex physical processes in future work. Despite increased potential evapotranspiration under rising temperatures, both CMIP5 simulations and thermodynamic principles suggest that the soil moisture-temperature feedback cannot support long-term enhanced evapotranspiration at the global scale. The dissipation of radiative forcing eventually shifts towards sensible heat flux and accelerates the warming over land, especially over South America and Europe.
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Phillips, Briana, and Larry O’Neill. "Observational Analysis of Extratropical Cyclone Interactions with Northeast Pacific Sea Surface Temperature Anomalies." Journal of Climate 33, no. 15 (August 1, 2020): 6745–63. http://dx.doi.org/10.1175/jcli-d-19-0853.1.
Повний текст джерелаАнотація:
AbstractThis study examines the interaction between a northeast Pacific upper-ocean thermal anomaly and individual fall storm events between 2013 and 2016. In 2013, a large upper-ocean thermal anomaly formed in the Gulf of Alaska (GOA) with sea surface temperatures (SST) warmer than 4°C above the climatological norm. Formation of the anomaly was associated with a persistent atmospheric ridge in the GOA that produced a lull in storm activity in the boreal winter of 2013/14. While reduced storm activity was the apparent cause of this SST anomaly, we present cases where extratropical cyclones significantly eroded its mixed layer heat content on synoptic time scales. Case studies during the 4-yr period 2013–16 using satellite and Argo hydrographic observations show that early fall storms produced the largest surface heat fluxes and the greatest cooling of SST. The magnitude of thermal energy transfer from the ocean to the atmosphere during individual storm events was then determined using vertically integrated heat budgets based on Argo temperature profiles and reanalysis surface heat fluxes. Storm-induced surface heat flux anomalies accounted for approximately 50% of the warm anomaly cooling observed by Argo profiles. This rapid heat loss occurred over time scales of approximately 3–5 days. The decay of the warm SST anomaly (SSTa) occurred much more quickly than expected from classic thermal damping by SST-induced turbulent heat fluxes, which may be attributed here at least partly to much shallower mixed layers during early fall. Analysis of the individual surface flux terms indicated that the latent heat flux was the dominant contributor to storm-induced heat exchange across the air–sea interface.
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Ouyang Haoyi, 欧阳浩艺, 陈婉钧 Chen Wanjun, 李海 Li Hai та 杨初平 Yang Chuping. "平整表面反射率异常的单像素检测理论". Laser & Optoelectronics Progress 58, № 12 (2021): 1212003. http://dx.doi.org/10.3788/lop202158.1212003.
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Zhang, Xuebin, and Michael J. McPhaden. "Eastern Equatorial Pacific Forcing of ENSO Sea Surface Temperature Anomalies*." Journal of Climate 21, no. 22 (November 15, 2008): 6070–79. http://dx.doi.org/10.1175/2008jcli2422.1.
Повний текст джерелаАнотація:
Abstract Previous studies have described the impacts of wind stress variations in the eastern Pacific on sea surface temperature (SST) anomalies associated with the El Niño–Southern Oscillation (ENSO) phenomenon. However, these studies have usually focused on individual El Niño events and typically have not considered impacts on La Niña—the cold phase of the ENSO cycle. This paper examines effects of wind stress and heat flux forcing on interannual SST variations in the eastern equatorial Pacific from sensitivity tests using an ocean general circulation model over the period 1980–2002. Results indicate that in the Niño-3 region (5°N–5°S, 90°–150°W) a zonal wind stress anomaly of 0.01 N m−2 leads to about 1°C SST anomaly and that air–sea heat fluxes tend to damp interannual SST anomalies generated by other physical processes at a rate of about 40 W m−2 (°C)−1. These results systematically quantify expectations from previous event specific numerical model studies that local forcing in the eastern Pacific can significantly affect the evolution of both warm and cold phases of the ENSO cycle. The results are also consistent with a strictly empirical analysis that indicates that a wind stress anomaly of 0.01 N m−2 leads to ∼1°C SST anomaly in the Niño-3 region.
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Yamamoto, M. "Meteorological impacts of sea-surface temperature associated with the humid airflow from Tropical Cyclone Talas (2011)." Annales Geophysicae 32, no. 7 (July 23, 2014): 841–57. http://dx.doi.org/10.5194/angeo-32-841-2014.
Повний текст джерелаАнотація:
Abstract. This paper examines meteorological impacts of sea-surface temperature (SST) in the presence of the humid airflow from Tropical Cyclone Talas (2011). To investigate the influence of the SST on the severe weather in and around Japan, sensitivity simulations were conducted using six SST data products covering a period of 7 days. The upward sea-surface latent heat flux that accumulated over the 7-day period was high around the Kuroshio during the slow passage of the tropical cyclone. Large differences were found among the individual SST products around the southern coast of Japan. The coastal warm SST anomaly of ~ 1.5 °C enhanced the surface upward latent heat fluxes (by 60 to 80%), surface southeasterly winds (by 6 to 8%), and surface water mixing ratios (by 4%) over the coastal sea area. The enhanced latent heat flux resulting from the coastal SST anomaly contributed to the further enhancement of the latent heat flux itself via a positive feedback with the amplified surface horizontal wind. The SST anomalies produced an anomaly in 7-day precipitation (ca. 40 mm) along the mountainsides and over a coastal area where the surface wind anomaly was locally large. Thus, coastal SST error is important in the atmospheric simulation of accumulated evaporation and precipitation associated with tropical cyclones making landfall.