Dynamics in a coupled-cavity array

The dynamics of a system composed of two coupled optical cavities, each containing a single two-level atom, is studied over a wide range of detuning and coupling values. A description of the field in terms of delocalized modes reveals that the detuning between the atoms and these modes is controlled by the coupling between the cavities; this detuning in turn governs the nature of the dynamics. If the atoms are highly detuned from both delocalized field modes, the dynamics becomes dispersive and an excitation may be transferred from the first atom to the second without populating the field. In the case of resonance between the atoms and one of the delocalized modes, state transfer between the atoms requires intermediate excitation of the field. Thus the interaction between the two atoms can be controlled by adjusting the coupling between the cavities.Comment: 11 pages, 3 figure

Responding to Sea Level Rise: Does Short-Term Risk Reduction Inhibit Successful Long-Term Adaptation?

Most existing coastal climate-adaptation planning processes, and the research supporting them, tightly focus on how to use land use planning, policy tools, and infrastructure spending to reduce risks from rising seas and changing storm conditions. While central to community response to sea level rise, we argue that the exclusive nature of this focus biases against and delays decisions to take more discontinuous, yet proactive, actions to adapt—for example, relocation and aggressive individual protection investments. Public policies should anticipate real estate market responses to risk reduction to avoid large costs—social and financial—when and if sea level rise and other climate-related factors elevate the risks to such high levels that discontinuous responses become the least bad alternative

Temporal and spatial dynamics of CO2 air-sea flux in the Gulf of Maine

Ocean surface layer carbon dioxide (CO2) data collected in the Gulf of Maine from 2004 to 2008 are presented. Monthly shipboard observations are combined with additional higher‐resolution CO2 observations to characterize CO2 fugacity ( fCO2) and CO2 flux over hourly to interannual time scales. Observed fCO2 andCO2 flux dynamics are dominated by a seasonal cycle, with a large spring influx of CO2 and a fall‐to‐winter efflux back to the atmosphere. The temporal results at inner, middle, and outer shelf locations are highly correlated, and observed spatial variability is generally small relative to the monthly to seasonal temporal changes. The averaged annual flux is in near balance and is a net source of carbon to the atmosphere over 5 years, with a value of +0.38 mol m−2 yr−1. However, moderate interannual variation is also observed, where years 2005 and 2007 represent cases of regional source (+0.71) and sink (−0.11) anomalies. We use moored daily CO2 measurements to quantify aliasing due to temporal undersampling, an important error budget term that is typically unresolved. The uncertainty of our derived annual flux measurement is ±0.26 mol m−2 yr−1 and is dominated by this aliasing term. Comparison of results to the neighboring Middle and South Atlantic Bight coastal shelf systems indicates that the Gulf of Maine exhibits a similar annual cycle and range of oceanic fCO2 magnitude but differs in the seasonal phase. It also differs by enhanced fCO2 controls by factors other than temperature‐driven solubility, including biological drawdown, fall‐to‐winter vertical mixing, and river runoff

Winter 1993 observations of oceanography and sediment transport at the LEO-15 site

The NOAA National Underseas Research Program at Rutgers University is establishing a Long-term Ecosystem Observatory off New Jersey in 15 meters of water. As part of a bottom boundary layer study at this site, WHOI deployed a bottom instrument frame during the winter of 1993-94. The bottom instrument carried a current meter, a vertical array of optical back scattering sensors, temperature, pressure and conductivity sensors and an Acoustical Backscattering Sensor. The deployment was partially successful as the acoustic system failed. The other instrumentation worked well for 3 weeks returning data on winter conditions at the site. The extreme winter waves ended the experiment by tipping the instrument over on its side. The optical instrumentation was calibrated with sediment from the site, and the results from the experiment presented.Funding was provided by the National Oceanic and Atmospheric Administration through Contract No. 4-25020 to Rutgers/SUNY National Underseas Research Program

Big-Bang Nucleosynthesis and Hadronic Decay of Long-Lived Massive Particles

We study the big-bang nucleosynthesis (BBN) with the long-lived exotic particle, called X. If the lifetime of X is longer than \sim 0.1 sec, its decay may cause non-thermal nuclear reactions during or after the BBN, altering the predictions of the standard BBN scenario. We pay particular attention to its hadronic decay modes and calculate the primordial abundances of the light elements. Using the result, we derive constraints on the primordial abundance of X. Compared to the previous studies, we have improved the following points in our analysis: The JETSET 7.4 Monte Carlo event generator is used to calculate the spectrum of hadrons produced by the decay of X; The evolution of the hadronic shower is studied taking account of the details of the energy-loss processes of the nuclei in the thermal bath; We have used the most recent observational constraints on the primordial abundances of the light elements; In order to estimate the uncertainties, we have performed the Monte Carlo simulation which includes the experimental errors of the cross sections and transfered energies. We will see that the non-thermal productions of D, He3, He4 and Li6 provide stringent upper bounds on the primordial abundance of late-decaying particle, in particular when the hadronic branching ratio of X is sizable. We apply our results to the gravitino problem, and obtain upper bound on the reheating temperature after inflation.Comment: 94 pages, 49 figures, to appear in Phys. Rev. D. This is a full length paper of the preprint astro-ph/040249

Instrumentation for open ocean aquaculture monitoring

The Woods Hole Oceanographic Institution is assisting the University of New Hampshire by instrumenting a fish cage and mooring as part of their Open Ocean Aquaculture demonstration program in the Gulf of Maine. To understand these systems, the wave and current forcing and the response of the mooring and fish cage needs to be measured. A UNH mooring with an ADCP measured the current forcing. Tension in the mooring lines was measured by load cells deployed with the mooring during servicing in August 2000. Load cells were placed in each anchor line, and, in the NE corner, also in the two grid lines and the riser line to the fish cage. Low power recording systems were deployed on the load cell mounting bars by divers on 22 October 2000, recorded good data through January 2001, when they were turned around and redeployed. Three single load cell recorders were recovered in July 2001 and recorded though 23 June when their data storage filled. The four load cell system was recovered in March after a large winter storm, and had failed in early March. The wave forcing was measured with a wave rider buoy with a 3-axis accelerometer measuring its motion. The acceleration was integrated twice to obtain wave displacement. The system mooring contained a compliant elastic. The wave rider was deployed on 4 January 2001 and recovered on 17 March 2001 after a major Northeast storm. It recorded data throughout its deployment. The motion of the moored fish cage was measured by a motion package constructed around a 6-axis Motion-Pak and a PC-104 data system. The motion package was deployed on the fish cage from Jan into March 2001 and recorded motions thoughout without difficuly. It observed a major storm in early March where the counter weight was lost from the fish cage, and its increase in motion thereafter.Fudning was provided by National Oceanic and Atmospheric Adminstration for the Open Ocean Aquaculture Project under Contract No. NA86RG0016 to the University of New Hampshire and under Subcontracts 00-394 and 01-442 to the Woods Hole Oceanographic Institution

Simultaneous spatial and temporal mesurements of the internal wave field during MATE

A statistical description of the deep ocean internal wave field is presented using measurements from the Midocean Acoustic Transmission Experiment, conducted near Cobb Seamount in the NE Pacific (46°46'N, 30°47'W) during June–July 1977. The unique feature of this experiment is the variety of data obtained simultaneously from the same location: time series of temperature and velocity, and vertical and horizontal profiles of temperature. A generalized form of the Garrett‐Munk (GM) internal wave spectrum is developed and used to interpret the data. This spectral model is specified by three parameters, Ē, t, and p (energy level, wave number bandwidth, and frequency spectral slope, respectively). The variety of measurement types permit these three model parameters to be estimated from more than one measurement. The overall best fit values to the MATE data were p = 2.7 (GM use p = 3), t = 3.1 m⁻¹ s (equivalent to j* = 6, twice the GM value), and Ē = 8 × 10⁻⁴ J/kg (within 20% of the GM level). Although significant differences were found in the values of the bandwidth (t) and spectral slope (p) from those specified by Garrett‐Munk, the deviations are consistent with the behavior expected in a random internal wave field