Observations of sound-speed fluctuations in the Beaufort Sea from summer 2016 to summer 2017

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kucukosmanoglu, M., Colosi, J. A., Worcester, P. F., Dzieciuch, M. A., & Torres, D. J. Observations of sound-speed fluctuations in the Beaufort Sea from summer 2016 to summer 2017. Journal of the Acoustical Society of America, 149(3), (2021): 1536-1548, https://doi.org/10.1121/10.0003601.Due to seasonal ice cover, acoustics can provide a unique means for Arctic undersea communication, navigation, and remote sensing. This study seeks to quantify the annual cycle of the thermohaline structure in the Beaufort Sea and characterize acoustically relevant oceanographic processes such as eddies, internal waves, near-inertial waves (NIWs), and spice. The observations are from a seven-mooring, 150-km radius acoustic transceiver array equipped with oceanographic sensors that collected data in the Beaufort Sea from 2016 to 2017. Depth and time variations of the sound speed are analyzed using isopycnal displacements, allowing a separation of baroclinic processes and spice. Compared to lower latitudes, the overall sound speed variability is small with a maximum root mean square of 0.6 m/s. The largest source of variability is spice, most significant in the upper 100 m, followed by eddies and internal waves. The displacement spectrum in the internal wave band is time dependent and different from the Garret-Munk (GM) spectrum. The internal wave energy varied with time averaging 5% of the GM spectrum. The spice sound-speed frequency spectrum has a form very different from the displacement spectrum, a result not seen at lower latitudes. Because sound speed variations are weak, observations of episodic energetic NIWs with horizontal currents up to 20 cm/s have potential acoustical consequences.This research was supported by the Office of Naval Research (ONR) and M.K. was supported by an ONR Ocean Acoustics Graduate Student Fellowship under Award No. N00014-19-1-2203. The 600 kHz ADCP and IPS ice draft data were supported by the ONR Arctic and Global Prediction Program (ONR 322AG) under Award No. N00014-15-1-2782. This material is based on work supported by the ONR under Award No. N00014-15-2068

Inter-annual variability of the acoustic propagation in the Mediterranean Sea identified from a synoptic monthly gridded database as compared with GDEM

The primary area of this research is to identify inter-annual variability of acoustic propagation in the Mediterranean Sea through comparison of sound speed profiles obtained from the synoptic monthly gridded World Ocean Database (SMD-WOD) and Generalized Digital Environmental Model (GDEM) temperature (T) and salinity (S) data. The SMG-WOD for the region of interest in this study has 0.25°×0.25° horizontal resolutions, 28 vertical levels from the surface to 3000-meter depth, one-month temporal increment from January 1960 to December 2014. It provides the long-term spatial and temporal variability of the (T, S) and sound speed profile data. However, the GDEM offers climatological monthly mean (T, S) data with 0.25 horizontal resolution and 78 vertical depths from the surface to 6600 meters. Five distinct points were chosen in order to model acoustic propagation to account for significant differences in mean salinity, temperature vertical profiles and bottom sediments between sub-basins. Overall, we found that the Levantine Surface Water (LSW) has the highest spiciness among the all water masses. We analyzed that transmission loss (TL) for each decade, and we found that there are inter-annual TL variabilities. TL does not show high inter-annual variabilities over convergence zone paths; however, it shows high inter-annual variability on surface duct, bottom bounce and sound channels.http://archive.org/details/interannualvaria1094551561Lieutenant Junior Grade, Turkish NavyApproved for public release; distribution is unlimited

Physical Oceanographic and Acoustic Observations of the Beaufort Sea and its Subsurface Duct Sensitivity to Deterministic Ocean Features

The Arctic Ocean is rapidly transforming due to climate change, and this thesis analyzes two, year-long ocean-acoustic data sets to quantify variability in the thermohaline, current and ice structure and examine the implications for acoustic propagation in the Beaufort Sea. The two field efforts are the Canada Basin AcousticPropagation Experiment (CANAPE) and the Coordinated Arctic Acoustic Thermometry Experiment (CAATEX). These results are important since acoustics offers a unique tool for the Arctic under ice communication, navigation, and remote sensing.A key acoustic feature of the Beaufort Sea is the Beaufort duct created by the Pacific winter water (PWW), which is sandwiched between the shallow Pacific summer water (PSW) and the deeper Atlantic water (AW). This is important because this duct allows for long-range transmission without lossy interactions with sea ice or surface waves. In general, we find this duct can trap from 2-6 acoustic modes in the frequency range between several tens of Hz and several hundreds of Hz. Since fluctuations can alter the number of trapped modes and affect Transmission loss, we have analyzed variability due to spice, internal waves, eddies, and near-inertial waves, and we find spicy thermohaline structure is observed to be the most significant source of variability in the top 100 m, followed by eddies and internal waves.Acoustic interaction with the ice cover is another critical factor affecting arctic acoustics, so we have analyzed high-frequency acoustic scattering statistics from the CANAPE. Five important surface scattering epochs were identified over the seasonal cycle: open water, initial ice formation, ice solidification, ice thickening, and ice melting. The most significant changes in statistics are seen during the formation, solidification, and melting. The statistical features are comparable throughout the CANAPE region, implying similar ice properties.The stability of acoustic propagation in the Beaufort duct is another aspect of this thesis. We analyzed the oceanographic measurements from the CANAPE and CAATEX, and focused on the problem of mode coupling in the Beaufort duct,induced by deterministic ocean features such as eddies and intrusions. Here we find that deterministic variability in the PSW due to spice and stronger halocline eddies can result in enhanced coupling between acoustic modes in and out of the BD. Here we use the mode interaction parameter (MIP), which is a non-dimensional quantity, Γmn that quantifies the mode coupling strength between mode m (a duct mode) and all the other n modes. Strong/moderate-weak coupling is determined by MIP greater-than/less-than 1. The MIP is a function of acoustic frequency and horizontal structure, which we define as the typical half-width of Gaussian perturbation (Δ) in this thesis. Our result showed that for both large and small Δ, Γmn goes to zero, and maximal coupling occurs when Δ ranges between 1.5 and 2.2 km

Effect of inter- and intra-annual thermohaline variability on acoustic propagation

This paper is to answer the question “How can inter- and intra-annual variability in the ocean be leveraged by the submarine Force?” through quantifying inter- and intra-annual variability in (T, S) fields and in turn underwater acoustic characteristics such as transmission loss, signal excess, and range of detection. The Navy’s Generalized Digital Environmental Model (GDEM) is the climatological monthly mean data and represents mean annual variability. An optimal spectral decomposition method is used to produce a synoptic monthly gridded (SMG) (T, S) dataset for the world oceans with 1o×1o horizontal resolution, 28 vertical levels (surface to 3,000 m depth), monthly time increment from January 1945 to December 2014 now available at the NOAA/NCEI website: http://data.nodc.noaa.gov/cgi- bin/iso?id=gov.noaa.nodc:0140938. The sound velocity decreases from 1945 to 1975 and increases afterwards due to global climate change. Effect of the inter- and intra-annual (T, S) variability on acoustic propagation in the Yellow Sea is investigated using a well-developed acoustic model (Bellhop) in frequencies from 3.5 kHz to 5 kHz with sound velocity profile (SVP) calculated from GDEM and SMG datasets, various bottom types (silty clay, fine sand, gravelly mud, sandy mud, and cobble or gravel) from the NAVOCEANO‘s High Frequency Environmental Algorithms (HFEVA), source and receiver depths. Acoustic propagation ranges are extended drastically due to the inter-annual variability in comparison with the climatological SVP (from GDEM). Submarines’ vulnerability of detection as its depth varies and avoidance of short acoustic range due to inter-annual variability are also discussed

Assessment of forest roads and firebreaks in Turkey

This paper describes the situaiton and assessment of forest roads and firebreaks in context of forest transportation and forest fire prevention in Turkey. In recent years, Turkey has lost many forest areas to forest fires, and this not only results in loss of life, property, and infrastructure, but also causes deterioration in the natural environment and degrades ecosystems. According to current status of Turkey, the numbers of forest fires and the areas that are burnt fluctate widely from year to year. In the last decade, the number of forest fires has increased, but the area burned per forest fire has decreased. The Turkish General Directorate of Forestry spent $82.92 million to fight forest fires in 2003 and$677.71 million over the last decade. As of the end of 2006, the total number of forest fires in Turkey since 1937 is 80 011, giving an average of 1143 fires per year. For the same period, the total forest area burned is 1 571 607 ha and the mean forest area burned per fire is 19.64 ha

The success of the Cystic Fibrosis Registry of Turkey for improvement of patient care

Background Cystic fibrosis (CF) registries play an essential role in improving disease outcomes of people with CF. This study aimed to evaluate the association of newly established CF registry system in Turkey on follow-up, clinical, growth, treatment, and complications of people with this disease. Methods Age at diagnosis, current age, sex, z-scores of weight, height and body mass index (BMI), neonatal screening results, pulmonary function tests, history of meconium ileus, medications, presence of microorganisms, and follow-up were evaluated and compared to data of people with CF represented in both 2017 and 2019 registry data. Results There were 1170 people with CF in 2017 and 1637 in 2019 CF registry. Eight hundred and fourteen people were registered in both 2017 and 2019 of whom z-scores of heights and BMI were significantly higher in 2019 (p = 0.002, p =0.039, respectively). Inhaled hypertonic saline, bronchodilator, and azithromycin usages were significantly higher in 2019 (p =0.001, p = 0.001, p = 0.003, respectively). The percent predicted of forced expiratory volume in 1 sec and forced vital capacity were similar in 2017 and 2019 (88% and 89.5%, p = 0.248 and 84.5% and 87%, p =0.332, respectively). Liver diseases and osteoporosis were significantly higher, and pseudo-Bartter syndrome (PBS) was significantly lower in 2019 (p = 0.011, p = 0.001, p = 0.001, respectively). Conclusions The z-scores of height and BMI were higher, the use of medications that protect and improve lung functions was higher and incidence of PBS was lower in 2019. It was predicted that registry system increased the care of people with CF regarding their follow-up. The widespread use of national CF registry system across the country may be beneficial for the follow-up of people with CF

The success of the Cystic Fibrosis Registry of Turkey for improvement of patient care

Background Cystic fibrosis (CF) registries play an essential role in improving disease outcomes of people with CF. This study aimed to evaluate the association of newly established CF registry system in Turkey on follow-up, clinical, growth, treatment, and complications of people with this disease. Methods Age at diagnosis, current age, sex, z-scores of weight, height and body mass index (BMI), neonatal screening results, pulmonary function tests, history of meconium ileus, medications, presence of microorganisms, and follow-up were evaluated and compared to data of people with CF represented in both 2017 and 2019 registry data. Results There were 1170 people with CF in 2017 and 1637 in 2019 CF registry. Eight hundred and fourteen people were registered in both 2017 and 2019 of whom z-scores of heights and BMI were significantly higher in 2019 (p = 0.002, p =0.039, respectively). Inhaled hypertonic saline, bronchodilator, and azithromycin usages were significantly higher in 2019 (p =0.001, p = 0.001, p = 0.003, respectively). The percent predicted of forced expiratory volume in 1 sec and forced vital capacity were similar in 2017 and 2019 (88% and 89.5%, p = 0.248 and 84.5% and 87%, p =0.332, respectively). Liver diseases and osteoporosis were significantly higher, and pseudo-Bartter syndrome (PBS) was significantly lower in 2019 (p = 0.011, p = 0.001, p = 0.001, respectively). Conclusions The z-scores of height and BMI were higher, the use of medications that protect and improve lung functions was higher and incidence of PBS was lower in 2019. It was predicted that registry system increased the care of people with CF regarding their follow-up. The widespread use of national CF registry system across the country may be beneficial for the follow-up of people with CF