The 2015 Plains Elevated Convection at Night Field Project

The central Great Plains region in North America has a nocturnal maximum in warm-season precipitation. Much of this precipitation comes from organized mesoscale convective systems (MCSs). This nocturnal maximum is counterintuitive in the sense that convective activity over the Great Plains is out of phase with the local generation of CAPE by solar heating of the surface. The lower troposphere in this nocturnal environment is typically characterized by a low-level jet (LLJ) just above a stable boundary layer (SBL), and convective available potential energy (CAPE) values that peak above the SBL, resulting in convection that may be elevated, with source air decoupled from the surface. Nocturnal MCS-induced cold pools often trigger undular bores and solitary waves within the SBL. A full understanding of the nocturnal precipitation maximum remains elusive, although it appears that bore-induced lifting and the LLJ may be instrumental to convection initiation and the maintenance of MCSs at night. To gain insight into nocturnal MCSs, their essential ingredients, and paths toward improving the relatively poor predictive skill of nocturnal convection in weather and climate models, a large, multiagency field campaign called Plains Elevated Convection At Night (PECAN) was conducted in 2015. PECAN employed three research aircraft, an unprecedented coordinated array of nine mobile scanning radars, a fixed S-band radar, a unique mesoscale network of lower-tropospheric profiling systems called the PECAN Integrated Sounding Array (PISA), and numerous mobile-mesonet surface weather stations. The rich PECAN dataset is expected to improve our understanding and prediction of continental nocturnal warm-season precipitation. This article provides a summary of the PECAN field experiment and preliminary findings

Global economic impacts of climate variability and change during the 20th century

Estimates of the global economic impacts of observed climate change during the 20th century obtained by applying five impact functions of different integrated assessment models (IAMs) are separated into their main natural and anthropogenic components. The estimates of the costs that can be attributed to natural variability factors and to the anthropogenic intervention with the climate system in general tend to show that: 1) during the first half of the century, the amplitude of the impacts associated with natural variability is considerably larger than that produced by anthropogenic factors and the effects of natural variability fluctuated between being negative and positive. These non-monotonic impacts are mostly determined by the low-frequency variability and the persistence of the climate system; 2) IAMs do not agree on the sign (nor on the magnitude) of the impacts of anthropogenic forcing but indicate that they steadily grew over the first part of the century, rapidly accelerated since the mid 1970's, and decelerated during the first decade of the 21st century. This deceleration is accentuated by the existence of interaction effects between natural variability and natural and anthropogenic forcing. The economic impacts of anthropogenic forcing range in the tenths of percentage of the world GDP by the end of the 20th century; 3) the impacts of natural forcing are about one order of magnitude lower than those associated with anthropogenic forcing and are dominated by the solar forcing; 4) the interaction effects between natural and anthropogenic factors can importantly modulate how impacts actually occur, at least for moderate increases in external forcing. Human activities became dominant drivers of the estimated economic impacts at the end of the 20th century, producing larger impacts than those of low-frequency natural variability. Some of the uses and limitations of IAMs are discussed

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Educational psychology : a practitioner-researcher model of teaching

xvii, 482 p. : ill. ; 25 cm

by William P. Fletcher, Jr.

The purpose of the study was to develop and test a block scheduling evaluation model. Conceptual development of the model was based on a review of the literature which targeted the components of the school program most consistently identified with scheduling type: instruction, school climate, student outcomes, and operating efficiency. The model included an interview with the principal, analysis of documents, survey of teachers, and survey of students. The model was pilot tested in three high schools in Western Virginia. The principals of the three pilot schools and the researcher evaluated the model according to preestablished evaluation criteria. The evaluation identified several improvements including: instrumentation refinements aimed at providing more detailed information on teacher concerns about preparation and planning on the block schedule; data analysis refinements centering on technology; inclusion of other indicators such as standardized test scores and cost analysis; and, expansion of data collection techniques centering on systematic observation over an extended period of time. iii ACKNOWLEDGMENTS I wish to express my sincere appreciation to my loving wife Susan and my children Leigh, Barbara, and Paul. I only hope that I can re-gain the time lost to you during the writing of this study and the many hours of classes and study that are represented with-in these pages. Your support and understanding made this page in this book possible. My love of learning and the desire to pursue my education I owe to my parents, Bill and Bunny Fletcher. Their dedication to and unconditional support of their children gives me constant inspiration. I also wish to express my sincere appreciation for support received from Dr. Wayne Worner of Virginia Polytechnic Institute a..

The 2015 Plains Elevated Convection At Night field project

The article of record as published may be found at http://dx.doi.org/10.1175/BAMS-D-15-00257.1The PECAN field campaign assembled a rich array of observations from lower-tropospheric profiling systems, mobile radars and mesonets, and aircraft over the Great Plains during June–July 2015 to better understand nocturnal mesoscale convective systems and their relationship with the stable boundary layer, the low-level jet, and atmospheric bores.National Science Foundation (NSF)AGS-1327695 (NSF)AGS-1359726 (NSF)AGS-1359645 (NSF)AGS-1359606 (NSF)AGS-1359098 (NSF)AGS-1359771 (NSF)AGS-1442054 (NSF)ATM-1359703 (NSF)AGS-1359720 (NSF)AGS-1359698 (NSF)AGS-136237 (NSF)AGS-1237404 (NSF)AGS-1359723 (NSF

The Problem of the Commons: Still Unsettled after 100 Years

The problem of the commons is more important to our lives and thus more central to economics than a century ago when Katharine Coman led off the first issue of the American Economic Review. As the US and other economies have grown, the carrying capacity of the planet--in regard to natural resources and environmental quality--has become a greater concern, particularly for common-property and open-access resources. The focus of this article is on some important, unsettled problems of the commons. Within the realm of natural resources, there are special challenges associated with renewable resources, which are frequently characterized by open-access. An important example is the degradation of openaccess fisheries. Critical commons problems are also associated with environmental quality. A key contribution of economics has been the development of market-based approaches to environmental protection. These instruments are key to addressing the ultimate commons problem of the twenty-first century-global climate change. (JEL Q15, Q21, Q22, Q25, Q54)