264 research outputs found
Future Shield/Future Storm
My purpose is to address operational issues related to Desert Shield and Desert Storm and implications for employment of U.S, armed forces in the emergent international order. I will structure my comments by asking three questions and, in the answers, will highlight issues and implications by relating Desert Shield to Future Shield and Desert Storm to Future Storm. The questions are: âą How do we go about creating Future Shield? âą How do we create the correlation of forces necessary to prevail in Future Storm with minimum casualties and damage? âą How do we organize to make best use of the forces committed
Exploiting satellite earth observation to quantify current global oceanic DMS flux and its future climate sensitivity
This is the final version of the article. Available from Wiley/AGU via the DOI in this record.We used coincident Envisat RA2 and AATSR temperature and wind speed data from 2008/2009 to calculate the global net sea-air flux of dimethyl sulfide (DMS), which we estimate to be 19.6 Tg S a-1. Our monthly flux calculations are compared to open ocean eddy correlation measurements of DMS flux from 10 recent cruises, with a root mean square difference of 3.1 ÎŒmol m-2 day-1. In a sensitivity analysis, we varied temperature, salinity, surface wind speed, and aqueous DMS concentration, using fixed global changes as well as CMIP5 model output. The range of DMS flux in future climate scenarios is discussed. The CMIP5 model predicts a reduction in surface wind speed and we estimate that this will decrease the global annual sea-air flux of DMS by 22% over 25 years. Concurrent changes in temperature, salinity, and DMS concentration increase the global flux by much smaller amounts. The net effect of all CMIP5 modelled 25 year predictions was a 19% reduction in global DMS flux. 25 year DMS concentration changes had significant regional effects, some positive (Southern Ocean, North Atlantic, Northwest Pacific) and some negative (isolated regions along the Equator and in the Indian Ocean). Using satellite-detected coverage of coccolithophore blooms, our estimate of their contribution to North Atlantic DMS emissions suggests that the coccolithophores contribute only a small percentage of the North Atlantic annual flux estimate, but may be more important in the summertime and in the northeast Atlantic
Different flavours of oxygen help quantify seasonal variations of the biological carbon pump in the Celtic Sea
Shelf seas represent only 10% of the Worldâs Ocean by area but support up to 30% of its primary production. There are few measurements of biological production at high spatial and temporal resolution in these physically and biologically dynamic systems. Here, we use dissolved oxygen to-argon (O2/Ar) ratios and oxygen triple isotopes in O2 (16O, 17O, 18O) to estimate net community production, N(O2/Ar), and gross O2 production, G(17O), in summer and autumn 2014 and spring and summer 2015 in the Celtic Sea, as part of the UK Shelf-Sea Biogeochemistry Programme. Surface O2/Ar concentration ratios were measured continuously using a shipboard membrane inlet mass spectrometer. Additional depth profiles of O2/Ar concentration ratios, ÎŽ(17O) and ÎŽ(18O) were measured in discrete water samples from hydrocasts. The data were combined with wind-speed based gas exchange parameterisations to calculate biological air-sea oxygen fluxes. These fluxes were corrected for diapycnal diffusion, entrainment, production below the mixed layer, and changes over time to derive N(O2/Ar) and G(17O). The Celtic Sea showed the highest G(17O) in summer 2014 (825 mmol mâ2 dâ1) and lowest during autumn 2014 (153 mmol mâ2 dâ1). N(O2/Ar) was highest in spring 2015 (43 mmol mâ2 dâ1), followed by summer 2014 (42 mmol mâ2 dâ1), with a minimum in autumn 2014 (â24 mmol mâ2 dâ1). Dividing the survey region into three hydrographically distinct areas (Celtic Deep, Central Celtic Sea and Shelf Edge), we found that Celtic Deep and Shelf Edge had higher N(O2/Ar) in summer (71 and 63 mmol mâ2 dâ1, respectively) than in spring (49 and 22 mmol mâ2 dâ1). This study shows regional differences in the metabolic balance within the same season, as well as higher net community production in summer than in spring in some areas and years. The seasonal patterns in biological production rates and the export efficiency (f-ratio) identified the importance of biology for supporting the Celtic Seaâs ability to act as a net CO2 sink. Our measurements thus help improve our understanding of the biological carbon pump in temperate shelf seas
On arrangement and expression of love poem in Kokin-wakashu
<p>Annual integrated net flux with rain components, <i>F</i><sub><i>T</i></sub> (Tg C yr<sup>-1</sup>) from 1999â2006, for each of the ocean basins, and the impact of each rain component on <i>F</i><sub><i>T</i></sub> (Tg C yr<sup>-1</sup>), where <i>F</i><sub><i>T</i></sub> = <i>F</i><sub><i>DIC</i></sub> + <i>F</i><sub><i>k-rain</i></sub> and all-rain = <i>F</i><sub><i>T</i></sub><i>âF</i><sub><i>ref</i></sub>.</p
Spatial ecology of loggerhead turtles: Insights from stable isotope markers and satellite telemetry
This is the final version. Available on open access from Wiley via the DOI in this recordAim
Using a combination of satellite telemetry and stable isotope analysis (SIA), our aim was to identify foraging grounds of loggerhead turtles (Caretta caretta) at important rookeries in the Mediterranean, examine foraging ground fidelity, and across 25 years determine the proportion of nesting females recruiting from each foraging region to a major rookery in Cyprus.
Location
Mediterranean Sea.
Methods
Between 1993 and 2018, we investigated the spatial ecology of loggerhead turtles from rookeries in Cyprus and Greece using satellite telemetry (n = 55 adults) and SIA of three elements (n = 296).
Results
Satellite telemetry from both rookeries revealed the main foraging areas as the Adriatic region (Cyprus: 4% of individuals, Greece: 55%), Tunisian Plateau (Cyprus: 16%, Greece: 40%) and the eastern Mediterranean (Cyprus: 80%, Greece: 5%). Combining satellite telemetry and SIA allowed 64% of all nesting females to be assigned to; the Adriatic region (Cyprus: 2%, Greece: 38.5%), Tunisian Plateau (Cyprus: 47%, Greece: 38.5%) and the eastern Mediterranean (Cyprus: 51%, Greece: 23%), which are markedly different to proportions obtained using satellite telemetry. The proportion of the Cyprus nesting cohort using each foraging region did not change significantly, with the exception that individuals foraging in the Adriatic region are only present in the Cyprus nesting population from 2012. Repeat satellite tracking (n = 3) and temporal consistency in isotope ratios (n = 36) of Cyprus females, strongly suggest foraging ground fidelity over multiple decades.
Main conclusions
This study demonstrates the advantages of combining satellite telemetry and SIA to investigate spatial ecology at a population level. The importance of the Tunisian Plateau for foraging is demonstrated. This study indicates that females generally show high fidelity to foraging grounds and shows a potential recent shift to foraging in the Adriatic region for Cyprus females, while the importance of other regions persists across decades, thus providing baselines to develop and assess conservation strategies.Natural Environment Research Council (NERC
Effects of Nosema apis, N. ceranae, and coinfections on honey bee (Apis mellifera) learning and memory
Western honey bees (Apis mellifera) face an increasing number of challenges that in recent years have led to significant economic effects on apiculture, with attendant consequences for agriculture. Nosemosis is a fungal infection of honey bees caused by either Nosema apis or N. ceranae. The putative greater virulence of N. ceranae has spurred interest in understanding how it differs from N. apis. Little is known of effects of N. apis or N. ceranae on honey bee learning and memory. Following a Pavlovian model that relies on the proboscis extension reflex, we compared acquisition learning and long-term memory recall of uninfected (control) honey bees versus those inoculated with N. apis, N. ceranae, or both. We also tested whether spore intensity was associated with variation in learning and memory. Neither learning nor memory differed among treatments. There was no evidence of a relationship between spore intensity and learning, and only limited evidence of a negative effect on memory; this occurred only in the co-inoculation treatment. Our results suggest that if Nosema spp. are contributing to unusually high colony losses in recent years, the mechanism by which they may affect honey bees is probably not related to effects on learning or memory, at least as assessed by the proboscis extension reflex
Data-based estimates of the ocean carbon sink variability â First results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)
Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global seaâair CO2 fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types â taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global seaâair CO2 flux of 0.31 PgC yrâ1 (standard deviation over 1992â2009), which is larger than simulated by biogeochemical process models. From a decadal perspective, the global ocean CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean CO2 sink estimated by the SOCOM ensemble is â1.75 PgC yrâ1 (1992â2009), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trend
Terahertz two-cylinder waveguide coupler for transverse-magnetic and transverse-electric mode operation
We report the coupling and guiding of broadband terahertz radiation using a two-cylinder waveguide coupler. For the transverse electromagnetic TEM (TM0) geometry, the two opposing metal cylinders exhibit an amplitude transmission comparable to that of the cylindrical silicon lens coupled parallel-plate waveguide, but in the transverse-electric orientation the two-cylinder coupler shows much better amplitude transmission.Peer reviewedElectrical and Computer Engineerin
Controls on OpenâOcean North Atlantic ÎpCO2 at Seasonal and Interannual Time Scales Are Different
The North Atlantic is a substantial sink for anthropogenic CO2. Understanding the mechanisms driving the sink's variability is key to assessing its current state and predicting its potential response to global climate change. Here we apply a time series decomposition technique to satellite and in situ data to examine separately the factors (both biological and nonbiological) that affect the seaâair CO2 difference (ÎpCO2) on seasonal and interannual time scales. We demonstrate that on seasonal time scales, the subpolar North Atlantic ÎpCO2 signal is predominantly correlated with biological processes, whereas seawater temperature dominates in the subtropics. However, the same factors do not necessarily control ÎpCO2 on interannual time scales. Our results imply that the mechanisms driving seasonal variability in ÎpCO2 cannot necessarily be extrapolated to predict how ÎpCO2, and thus the North Atlantic CO2 sink, may respond to increases in anthropogenic CO2 over longer time scales
- âŠ