Evaluating Consistency of Snow Water Equivalent Retrievals from Passive Microwave Sensors over the North Central U. S.: SSM/I vs. SSMIS and AMSR-E vs. AMSR2

For four decades, satellite-based passive microwave sensors have provided valuable snow water equivalent (SWE) monitoring at a global scale. Before continuous long-term SWE records can be used for scientific or applied purposes, consistency of SWE measurements among different sensors is required. SWE retrievals from two passive sensors currently operating, the Special Sensor Microwave Imager Sounder (SSMIS) and the Advanced Microwave Scanning Radiometer 2 (AMSR2), have not been fully evaluated in comparison to each other and previous instruments. Here, we evaluated consistency between the Special Sensor Microwave/Imager (SSM/I) onboard the F13 Defense Meteorological Satellite Program (DMSP) and SSMIS onboard the F17 DMSP, from November 2002 to April 2011 using the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) for continuity. Likewise, we evaluated consistency between AMSR-E and AMSR2 SWE retrievals from November 2007 to April 2016, using SSMIS for continuity. The analysis is conducted for 1176 watersheds in the North Central U.S. with consideration of difference among three snow classifications (Warm forest, Prairie, and Maritime). There are notable SWE differences between the SSM/I and SSMIS sensors in the Warm forest class, likely due to the different interpolation methods for brightness temperature (Tb) between the F13 SSM/I and F17 SSMIS sensors. The SWE differences between AMSR2 and AMSR-E are generally smaller than the differences between SSM/I and SSMIS SWE, based on time series comparisons and yearly mean bias. Finally, the spatial bias patterns between AMSR-E and AMSR2 versus SSMIS indicate sufficient spatial consistency to treat the AMSR-E and AMSR2 datasets as one continuous record. Our results provide useful information on systematic differences between recent satellite-based SWE retrievals and suggest subsequent studies to ensure reconciliation between different sensors in long-term SWE records

Healthiness from Duality

Healthiness is a good old question in program logics that dates back to Dijkstra. It asks for an intrinsic characterization of those predicate transformers which arise as the (backward) interpretation of a certain class of programs. There are several results known for healthiness conditions: for deterministic programs, nondeterministic ones, probabilistic ones, etc. Building upon our previous works on so-called state-and-effect triangles, we contribute a unified categorical framework for investigating healthiness conditions. We find the framework to be centered around a dual adjunction induced by a dualizing object, together with our notion of relative Eilenberg-Moore algebra playing fundamental roles too. The latter notion seems interesting in its own right in the context of monads, Lawvere theories and enriched categories.Comment: 13 pages, Extended version with appendices of a paper accepted to LICS 201

Description of Liquid Nitrogen Experimental Test Facility

The Liquid Nitrogen Test Facility is a unique test facility for ground-based liquid nitrogen experimentation. The test rig consists of an insulated tank of approximately 12.5 cubic ft in volume, which is supplied with liquid nitrogen from a 300 gal dewar via a vacuum jacketed piping system. The test tank is fitted with pressure and temperature measuring instrumentation, and with two view ports which allow visual observation of test conditions. To demonstrate the capabilities of the facility, the initial test program is briefly described. The objective of the test program is to measure the condensation rate by injecting liquid nitrogen as a subcooled spray into the ullage of a tank 50 percent full of liquid nitrogen at saturated conditions. The condensation rate of the nitrogen vapor on the subcooled spray can be analytically modeled, and results validated and corrected by experimentally measuring the vapor condensation on liquid sprays

Magnetic structures of RbCuCl_3 in a transverse field

A recent high-field magnetization experiment found a phase transition of unknown character in the layered, frustrated antiferromagnet RbCuCl_3, in a transverse field (in the layers). Motivated by these results, we have examined the magnetic structures predicted by a model of RbCuCl_3, using the classical approximation. At small fields, we obtain the structure already known to be optimal, an incommensurate (IC) spiral with wave vector q in the layers. At higher fields, we find a staircase of long-period commensurate (C) phases (separated initially by the low-field IC phase), then two narrow IC phases, then a fourth IC phase (also with intermediate C phases), and finally the ferromagnetically aligned phase at the saturation field H_S. The three-sublattice C states familiar from the theory of the triangular antiferromagnet are never optimal. The C phases and the two intermediate IC phases were previously unknown in this context. The magnetization is discontinuous at a field \approx 0.4H_S, in qualitative agreement with experiment, though we find much fine structure not reported.Comment: 9 pages, 8 figure

Preliminary tests of an advanced high-temperature combustion system

A combustion system has been developed to operate efficiently and with good durability at inlet pressures to 4.05 MPa (40 atm), inlet air temperatures to 900 K, and exhaust gas temperatures to 2480 K. A preliminary investigation of this system was conducted at inlet pressures to 0.94 MPa (9 atm), a nominal inlet air temperature of 560 K, and exhaust gas temperatures to 2135 K. A maximum combustion efficiency of 98.5 percent was attained at a fuel-air ratio of 0.033; the combustion efficiency decreased to about 90 percent as the fuel-air ratio was increased to 0.058. An average liner metal temperature of 915 K, 355 kelvins greater than the nominal inlet air temperature, was reached with an average exhaust gas temperature of 2090 K. The maximum local metal temperature at this condition was about 565 kelvins above the nominal inlet air temperature and decreased to 505 kelvins above with increasing combustor pressure. Tests to determine the isothermal total pressure loss of the combustor showed a liner loss of 1.1 percent and a system loss of 6.5 percent

FLORAE MALESIANAE PRAECURSORES XLVII. CENSUS OF MALESIAN CASTANOPSIS (FAGACEAE)

This paper deals with the names and typication of the 34 species recognized in Malesia. Specimens important for the knowledge of the distribution of each species have been cited with their locality. Indexes to names and to all examined specimens are given. Ten new species are described: Castanopsis clemensii, densinervia, endertii, microphylla,, oligoneura, oviformis, paucispina, peduneulata, psilophylla, all from Borneo, and johorensis from Malaya. C. hypophoenieea and C. lucida are new combinations based on Quercus hypophoenieea v. Seem, and Alseodaphne lucida Nees in Wall, respectively. Castanopsis ebneri and woodii are reduced to evansii, hullettii to lucida, pachycarpa to rhamnifolia, conspersispina, to tungurrut, dispersispina to hypophoenieea, ridleyi partly to tungurrut and partly to megacarpa, kinabaluensis to foxworthyi, pearsonii to mottleyana, junghuhnii and schlenkerae to acuniinatissima. Castanopsis selangorensis A. Cam. is regarded as a doubtful species. The number of endemic species is for Malaya 5, Borneo 11, the Philippines 1; the total number of species, is for Sumatra 11, Malaya 17, Java 4, Borneo 20, the Philippines 4, Celebes 2, the Moluccas 1, New Guinea 1, the Lesser Sunda Islands none

A simple formula for pooling knowledge about a quantum system

When various observers obtain information in an independent fashion about a classical system, there is a simple rule which allows them to pool their knowledge, and this requires only the states-of-knowledge of the respective observers. Here we derive an equivalent quantum formula. While its realm of applicability is necessarily more limited, it does apply to a large class of measurements, and we show explicitly for a single qubit that it satisfies the intuitive notions of what it means to pool knowledge about a quantum system. This analysis also provides a physical interpretation for the trace of the product of two density matrices.Comment: 5 pages, Revtex

Phonon number quantum jumps in an optomechanical system

We describe an optomechanical system in which the mean phonon number of a single mechanical mode conditionally displaces the amplitude of the optical field. Using homodyne detection of the output field we establish the conditions under which phonon number quantum jumps can be inferred from the measurement record: both the cavity damping rate and the measurement rate of the phonon number must be much greater than the thermalization rate of the mechanical mode. We present simulations of the conditional dynamics of the measured system using the stochastic master equation. In the good-measurement limit, the conditional evolution of the mean phonon number shows quantum jumps as phonons enter and exit the mechanical resonator via the bath.Comment: 13 pages, 4 figures. minor revisions since first versio

Dental Professionals in Non-Dental Settings

This report focuses on nine oral health innovations seeking to increase access to preventive oral health care in nondental settings. Two additional reports in this series describe the remaining programs that provide care in dental settings and care to young children. The nine innovations described here integrate service delivery and workforce models in order to reduce or eliminate socioeconomic, geographic, and cultural barriers to care. Although the programs are diverse in their approaches as well as in the specific characteristics of the communities they serve, a common factor among them is the implementation of multiple strategies to increase the number of children from low-income families who access preventive care, and also to engage families and communities in investing in and prioritizing oral health. For low-income children and their families, the barriers that must be addressed to increase access to preventive oral health care are numerous. For example, even children covered by public insurance programs face a shortage of dentists that accept Medicaid and who specialize in pediatric dentistry. The effects of poverty intersect with other barriers such as living in remote geographic areas and having a community-wide history of poor access to dental care in populations such as recent immigrants. Overcoming these barriers requires creative strategies that address transportation barriers, establish welcoming environments for oral health care, and are linguistically and culturally relevant. Each of these nine programs is based on such strategies, including:-Expanding the dental workforce through training new types of providers or adding new providers to the workforce toincrease reach and community presence;-Implementing new strategies to increase the cost-effectiveness of care so that more oral health care services are available and accessible;-Providing training and technical assistance that increase opportunities for and competence in delivering oral health education and care to children;-Offering oral health care services in existing, familiar community venues such as schools, Head Start programs and senior centers;-Developing creative service delivery models that address transportation and cultural barriers as well as the fear and stigma associated with dental care that may arise in communities with historically poor access.The findings from the EAs of these programs are synthesized to highlight diverse and innovative strategies for overcoming barriers to access. These strategies have potential for rigorous evaluation and could emerge as best practices. If proven effective, these innovative program elements could then be disseminated and replicated to increase access for populations in need of preventive oral health care