Size-resolved evaluation of simulated deep tropical convection

Deep moist convection is an inherently multiscale phenomenon with organization processes coupling convective elements to larger-scale structures. A realistic representation of the tropical dynamics demands a simulation framework that is capable of representing physical processes across a wide range of scales. Therefore, storm-resolving numerical simulations at 2.4 km have been performed covering the tropical Atlantic and neighboring parts for 2 months. The simulated cloud fields are combined with infrared geostationary satellite observations, and their realism is assessed with the help of object-based evaluation methods. It is shown that the simulations are able to develop a well-defined intertropical convergence zone. However, marine convective activity measured by the cold cloud coverage is considerably underestimated, especially for the winter season and the western Atlantic. The spatial coupling across the resolved scales leads to simulated cloud number size distributions that follow power laws similar to the observations, with slopes steeper in winter than summer and slopes steeper over ocean than over land. The simulated slopes are, however, too steep, indicating too many small and too few large tropical cloud cells. It is also discussed that the number of larger cells is less influenced by multiday variability of environmental conditions. Despite the identified deficits, the analyzed simulations highlight the great potential of this modeling framework for process-based studies of tropical deep convection. © 2018 American Meteorological Society

Living with Alzheimer’s Disease: A Study of Adult Day Health Services in Massachusetts

The role of adult day health care (ADHC) is gaining increased attention as the nation prepares for the large cohort of baby boomers entering their later years. Many boomers are aging with physical and cognitive impairments, including Alzheimer\u27s disease and related dementias. Projections indicate that Massachusetts, along with the nation as a whole, is experiencing an increasing rate of older persons as baby boomers enter late-life. The Commonwealth can expect that persons with Alzheimer\u27s disease and their care partners will need community-based services that are specifically designed for adults with cognitive impairments. However, a report by the Robert Wood Johnson Foundation found that there is a serious lack of adult day care services for the state\u27s elderly population. The 2003 report found that Massachusetts is only meeting 62% of needs for adults with physical and cognitive impairments, and at least 78 more programs are needed in the state. Yet, programs in Massachusetts continue to close. The specific objectives of the study were to: (1) describe existing practices of adult day health care services in Massachusetts for persons living with Alzheimer\u27s disease and related dementias, (2) explore programs that are specifically designed for participants who are in late-stage dementia, (3) address challenges that adult day health care services are now encountering, and (4) envision new paradigms for meeting the needs of persons with early-stage and early-onset dementia

When global climate models are able to differentiate between an elephant and a big mouse

Um alle 2,5 Kilometer auf der Erde den Zustand der Atmosphäre mit einem Klimamodell nachzurechnen, braucht es 83 Millionen Punkte. Nur so, und im Gegensatz zu gängigen Klimamodellen, die mit einer typischen Auflösung von rund 100 Kilometer arbeiten, lässt sich die Vielfalt der Wolken und ihre einzigartigen Formen, die manchmal an einen Elefanten, manchmal an eine große Maus erinnern, wiedergeben. Sind aber so viele Details nötig? Die Autoren präsentieren die Ergebnisse einer internationalen Vergleichsstudie, in der zum ersten Mal acht solcher neuartigen Klimamodelle gerechnet wurden.Eighty-three million points are needed to represent the atmospheric state every 2.5 km on Earth. Only such a grid spacing allows climate modelers to represent in their models the diversity of clouds, their small-scale details and their unique shapes which, at times, may remember elephants and, at other times, big mice. But are so many details that cannot be captured by current state-of-the-art climate models really necessary? In the following the authors present the results of an intercomparison exercise where, for the first time, eight of these next-generation climate models were run

An automated cirrus classification

Cirrus clouds play an important role in determining the radiation budget of the earth, but many of their properties remain uncertain, particularly their response to aerosol variations and to warming. Part of the reason for this uncertainty is the dependence of cirrus cloud properties on the cloud formation mechanism, which itself is strongly dependent on the local meteorological conditions. In this work, a classification system (Identification and Classification of Cirrus or IC-CIR) is introduced to identify cirrus clouds by the cloud formation mechanism. Using re-analysis and satellite data, cirrus clouds are separated in four main types: orographic, frontal, convective and synoptic. Through a comparison to convection-permitting model simulations and back- trajectory based analysis, it is shown that these observation-based regimes can provide extra information on the cloud scale updraughts and the frequency of occurrence of liquid-origin ice, with the convective regime having higher updraughts and a greater occurrence of liquid-origin ice compared to the synoptic regimes. Despite having different cloud formation mecha- nisms, the radiative properties of the regimes are not distinct, indicating that retrieved cloud properties alone are insufficient to completely describe them. This classification is designed to be easily implemented in GCMs, helping improve future model-observation comparisons and leading to improved parametrisations of cirrus cloud processe

Plasmas and Controlled Nuclear Fusion

Contsins reports on four research projects split into two sections.National Science Foundation (Grant GK-1165)National Science Foundation (Grant GK-57

Effect of the Milky Way on Magellanic Cloud structure

A combination of analytic models and n-body simulations implies that the structural evolution of the Large Magellanic Cloud (LMC) is dominated by its dynamical interaction with the Milky Way. Although expected at some level, the scope of the involvement has significant observational consequences. First, LMC disk orbits are torqued out of the disk plane, thickening the disk and populating a spheroid. The torque results from direct forcing by the Milky Way tide and, indirectly, from the drag between the LMC disk and its halo resulting from the induced precession of the LMC disk. The latter is a newly reported mechanism that can affect all satellite interations. However, the overall torque can not isotropize the stellar orbits and their kinematics remains disk-like. Such a kinematic signature is observed for nearly all LMC populations. The extended disk distribution is predicted to increase the microlensing toward the LMC. Second, the disk's binding energy slowly decreases during this process, puffing up and priming the outer regions for subsequent tidal stripping. Because the tidally stripped debris will be spatially extended, the distribution of stripped stars is much more extended than the HI Magellanic Stream. This is consistent with upper limits to stellar densities in the gas stream and suggests a different strategy for detecting the stripped stars. And, finally, the mass loss over several LMC orbits is predicted by n-body simulation and the debris extends to tens of kiloparsecs from the tidal boundary. Although the overall space density of the stripped stars is low, possible existence of such intervening populations have been recently reported and may be detectable using 2MASS.Comment: 15 pages, color Postscript figures, uses emulateapj.sty. Also available from http://www-astro.phast.umass.edu/~weinberg/weinberg-pubs.htm