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GIS for Surface Water: Using the National Hydrography Dataset, enables scientists, managers, and students to analyze the vital surface waters of the United States by combining the ready-to-use powers of a comprehensive database of the nation's waters and the ArcGIS platform for geographic data analysis and mapping-- Provided by publisher.

We quantify the oceanic sink for anthropogenic carbon dioxide (CO₂) over the period 1994 to 2007 by using observations from the global repeat hydrography program and contrasting them to observations from the 1990s. Using a linear regression–based method, we find a global increase in the anthropogenic CO₂ inventory of 34 ± 4 petagrams of carbon (Pg C) between 1994 and 2007. This is equivalent to an average uptake rate of 2.6 ± 0.3 Pg C year−1 and represents 31 ± 4% of the global anthropogenic CO₂ emissions over this period. Although this global ocean sink estimate is consistent with the expectation of the ocean uptake having increased in proportion to the rise in atmospheric CO₂, substantial regional differences in storage rate are found, likely owing to climate variability–driven changes in ocean circulation.

This volume constitutes the results of the International Conference on Underwater Environment, MOQESM'14, held at \"Le Quartz\" Conference Center in Brest, France, on October 14-15, 2014, within the framework of the 9th Sea Tech Week, International Marine Science and Technology Event. The objective of MOQESM'14 was to bring together researchers from both academia and industry, interested in marine robotics and hydrography with application to the coastal environment mapping and underwater infrastructures surveys. The common thread of the conference is the combination of technical control, perception, and localization, typically used in robotics, with the methods of mapping and bathymetry. The papers presented in this book focus on two main topics. Firstly, coastal and infrastructure mapping is addressed, focusing not only on hydrographic systems, but also on positioning systems, bathymetry, and remote sensing. The proposed methods rely on acoustic sensors such as side scan sonars, multibeam echo sounders, phase-measuring bathymetric sonars, as well as optical systems such as underwater laser scanners. Accurate underwater positioning is also addressed in the case of the use of a single acoustic beacon, and the latest advances in increasing the vertical precision of Global Navigation Satellite System (GNSS) are also presented. Most of the above mentioned works are closely related to autonomous marine vehicles. Consequently, the second part of the book describes some works concerning the methods associated with such type of vehicles. The selected papers focus on autonomous surface or underwater vehicles, detailing new approaches for localization, modeling, control, mapping, obstacle detection and avoidance, surfacing, and software development. Some of these works imply acoustics sensing as well as image processing. Set membership methods are also used in some papers. The applications of the work presented in this book concern in particular oceanography, monitoring of oil and gas infrastructures, and military field.

Dams contribute to water security, energy supply, and flood protection but also fragment habitats of freshwater species. Yet, a global species-level assessment of dam-induced fragmentation is lacking. Here, we assessed the degree of fragmentation of the occurrence ranges of ∼10,000 lotic fish species worldwide due to ∼40,000 existing large dams and ∼3,700 additional future large hydropower dams. Per river basin, we quantified a connectivity index (CI) for each fish species by combining its occurrence range with a high-resolution hydrography and the locations of the dams. Ranges of nondiadromous fish species were more fragmented (less connected) (CI = 73 ± 28%; mean ± SD) than ranges of diadromous species (CI = 86 ± 19%). Current levels of fragmentation were highest in the United States, Europe, South Africa, India, and China. Increases in fragmentation due to future dams were especially high in the tropics, with declines in CI of ∼20 to 40 percentage points on average across the species in the Amazon, Niger, Congo, Salween, and Mekong basins. Our assessment can guide river management at multiple scales and in various domains, including strategic hydropower planning, identification of species and basins at risk, and prioritization of restoration measures, such as dam removal and construction of fish bypasses.

\"A practical guide to the latest remote and in situ techniques used to measure sediments, quantify seabed characteristics, and understand physical properties of water and sediments and transport mechanisms in estuaries and coastal waters. Covering a broad range of topics from global reference frames and bathymetric surveying methods to the use of remote sensing for determining surface-water variables, enough background is included to explain how each technology functions. The advantages and disadvantages of each technology are explained, and a review of recent fieldwork experiments demonstrates how modern methods apply in real-life estuarine and coastal campaigns. Clear explanations of physical processes show links between different disciplines, making the book ideal for students and researchers in the environmental sciences, marine biology, chemistry and geology, whose work relies on an understanding of the physical environment and the way it is changing as a result of climate change, engineering and other influences\"-- Provided by publisher.

The magnitude of stream and river carbon dioxide (CO₂) emission is affected by seasonal changes in watershed biogeochemistry and hydrology. Global estimates of this flux are, however, uncertain, relying on calculated values for CO₂ and lacking spatial accuracy or seasonal variations critical for understanding macroecosystem controls of the flux. Here, we compiled 5,910 direct measurements of fluvial CO₂ partial pressure and modeled them against watershed properties to resolve reach-scale monthly variations of the flux. The direct measurements were then combined with seasonally resolved gas transfer velocity and river surface area estimates from a recent global hydrography dataset to constrain the flux at the monthly scale. Globally, fluvial CO₂ emission varies between 112 and 209 Tg of carbon per month. The monthly flux varies much more in Arctic and northern temperate rivers than in tropical and southern temperate rivers (coefficient of variation: 46 to 95 vs. 6 to 12%). Annual fluvial CO₂ emission to terrestrial gross primary production (GPP) ratio is highly variable across regions, ranging from negligible (<0.2%) to 18%. Nonlinear regressions suggest a saturating increase in GPP and a nonsaturating, steeper increase in fluvial CO₂ emission with discharge across regions, which leads to higher percentages of GPP being shunted into rivers for evasion in wetter regions. This highlights the importance of hydrology, in particular water throughput, in routing terrestrial carbon to the atmosphere via the global drainage networks. Our results suggest the need to account for the differential hydrological responses of terrestrial–atmospheric vs. fluvial–atmospheric carbon exchanges in plumbing the terrestrial carbon budget.

Aboobacker, V.M.; Abdulla, C.P.; Al-Ansari, E.M.A.S., and Vethamony, P., 2024. Impacts of shamal and nashi winds on the hydrodynamics along the northeast coast of Qatar, central Arabian Gulf. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 609-613. Charlotte (North Carolina), ISSN 0749-0208. The Arabian Gulf (hereafter the “Gulf”), a semi-enclosed basin with a maximum depth of 100 m, is connected to the Sea of Oman through the Strait of Hormuz. The seawater properties of the Gulf are nearly stable due to the exchange between the Sea of Oman and Gulf induced by the wind-driven surface inflow and the density-driven deepwater outflow. The currents in the Gulf were broadly studied, however, the characteristics of nearshore currents in the Qatar waters have not been investigated so far. This study presents the typical features identified from the measurements at a nearshore location along the east coast of Qatar, namely off Fuwairit (northeast cost; 7m depth). The analysis reveals that the northwesterly shamal and easterly nashi winds have significant role in the hydrodynamic circulation along the east coast of Qatar. During shamal events, the southeasterly/east-southeasterly flow was enhanced, while the north-westerly flow was diminished, since the wind-induced flow was followed the tidal ebb flows, and the opposite was true during flood flows. When the shamal was very strong, it has even nullified the tidal flows. A continuous south-eastward flow for a period of 48 hours have been identified during such an event. During strongest nashi winds, the northwestward flow off Fuwairit has been enhanced, while the southeastward flow has been diminished. The surface winds obtained from ERA5 and the surface currents obtained from the Copernicus Marine Environment Monitoring Services (CMEMS) has been used to further elaborate on the shamal and nashi wind effects on the Gulf circulation.

Aboobacker, V.M; Hasna, V.M.; Al-Ansari, E.M.A.S., and Vethamony, P., 2024. Nearshore hydrography along the coast of Doha, central Arabian Gulf. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 422-426. Charlotte (North Carolina), ISSN 0749-0208. Doha, the capital city of the State of Qatar has undergone substantial growth in population and infrastructure in the past few decades. Extensive land reclamation has resulted in changes in coastal morphology, especially on Doha Bay, the Pearl and the Lusail. Doha Bay is a semi-enclosed water body in the central east coast of Qatar. The characteristics of hydrography in the Doha Bay and adjacent regions are not well studied. This study presents the analysis of temperature, salinity, density, dissolved oxygen (DO), pH and chlorophyll-a collected off Doha (<15 m depth locations; 7 stations in all seasons; 4 other stations in 2 latest seasons) during October 2021, December 2021, June 2022 (pre-FIFA-2022), and March 2023 (post-FIFA-2022) using SeaBird CTD. The analysis reveals that the seasonal variations in temperature, salinity, density, DO and pH are statistically significant, while the horizontal variations are not significant. The chlorophyll-a has significant horizontal variability, while seasonal variability is not significant. There are four outfalls in Doha Bay, which discharges non-storm waters including groundwaters in limited quantity (0.114-1.241 m3/s). However, the changes in hydrographic parameters in the vicinity of the outfalls are marginal, except for DO. This has been verified when analysed the parameters during pre-FIFA-2022 (with discharges) and post-FIFA-2022 (no discharges) conditions. The sea surface temperature off Doha ranges from 27.8-29.0°C, 22.5-23.7°C, 28.0-29.2°C and 20.6-22.2°C, respectively, during the four seasons. The sea surface salinity ranges 39.3-40.6, 39.4-40.3, 37.3-39.2 and 40.6-42.0, respectively. The lowest salinity is obtained during summer, while the highest is obtained during winter; the latter is due to the relatively higher evaporation induced by winter shamal winds. The DO ranges 5.9-6.4, 6.5-6.8, 5.9-6.7 and 7-7.3 mg/l, respectively. The temporary closure of outfalls during FIFA-2022 has resulted in significant increase in DO, in addition to the well-mixing due to winter shamal winds. The pH ranges 7.80-7.90, 7.97-8.02, 7.86-7.99 and 7.70-7.77, respectively. The chlorophyll-a ranges 0.22-0.91, 0.17-1.45, 0.15-1.69 and 0.22-1.0 µg/l, respectively.

The GO-SHIP nutrient manual covers all aspects of nutrient analysis from basic sample collection and storage, specifically for Continuous Flow analysis using an Auto-Analyzer, and describes some specific nutrient methods for Nitrate, Nitrite, Silicate, Phosphate and Ammonium that are in use by many laboratories carrying out at-sea analysis and repeat hydrography sections across the world. The focus is on segmented flow analyzers not flow injection analyzers. It also covers laboratory best practices including quality control and quality assurance (QC/QA) procedures to obtain the best results, and suggests protocols for the use of reference materials (RM) and certified reference materials (CRMs).

We examine the historical evolution and projected changes in the hydrography of the deep basin of the Arctic Ocean in 23 climate models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). The comparison between historical simulations and observational climatology shows that the simulated Atlantic Water (AW) layer is too deep and thick in the majority of models, including the multi‐model mean (MMM). Moreover, the halocline is too fresh in the MMM. Overall our findings indicate that there is no obvious improvement in the representation of the Arctic hydrography in CMIP6 compared to CMIP5. The climate change projections reveal that the sub‐Arctic seas are outstanding warming hotspots, causing a strong warming trend in the Arctic AW layer. The MMM temperature increase averaged over the upper 700 m at the end of the 21st century is about 40% and 60% higher in the Arctic Ocean than the global mean in the SSP245 and SSP585 scenarios, respectively. Salinity in the upper few hundred meters is projected to decrease in the Arctic deep basin in the MMM. However, the spread in projected salinity changes is large and the tendency toward stronger halocline in the MMM is not simulated by all the models. The identified biases and projection uncertainties call for a concerted effort for major improvements of coupled climate models. Plain Language Summary Coupled climate models are crucial tools for understanding and projecting climate change, especially for the Arctic where the climate is changing at unprecedented rates. A cold fresh layer of water (aka halocline) has been protecting sea‐ice at the surface from the warm layer of water (aka Atlantic Water layer) which flows underneath and could potentially accelerate sea ice melting from below. Climate change disturbs this vertical structure by changing the temperature and salinity of the Arctic Ocean (in a process known as Atlantification and Pacification) which may lead to additional sea ice basal melting and accelerate sea ice decline. We examined the simulated temperature and salinity in the Arctic Ocean deep basin in state‐of‐the‐art climate model simulations which provided the basis for the IPCC Assessment Report. We found that although there are persistent inaccuracies in the representation of Arctic temperature and salinity, the Arctic Ocean below 100 m is subject to much stronger warming than the average global ocean. On the other hand, the upper Arctic Ocean salinity is projected to decrease, which on average may strengthen the isolation of sea ice from Atlantic Water heat in the Arctic deep basin area. Key Points A too deep and thick Arctic Atlantic Water layer continues to be a major issue in contemporary climate models contributing to the CMIP6 The Arctic Ocean below the halocline is subject to much stronger warming than the global mean during the 21st century The multi‐model mean upper ocean salinity is projected to decrease in the future but with high uncertainty