High-frequency single-board Doppler minisodar for precipitation measurements. Part I: Rainfall and hail

A high-frequency Doppler sodar for precipitation measurements has been developed. Such a Doppler sodar (6–20 kHz) can almost always measure precipitation and turbulence spectra simultaneously. Therefore, the mean vertical wind and spectral broadening effects can be directly removed. As the acoustic refractive indices for ice and liquid water are almost the same, the acoustic retrieval of precipitation can also be applied to rain with small hail (e.g., diameter D < 10 mm) or large hail, but for the latter, neglecting the effects of different orientations and shapes of hailstones. The authors’ single-board minisodar is based on the digital signal processing (DSP) technique. The first prototype has been continuously operated at a coastal weather station since 25 October 2002. For stratiform rain events, the minisodar showed good agreement with a Joss–Waldvogel disdrometer and an optical rain gauge. However, for convective heavy showers, the minisodar always observed higher rain rates. The continuous, nonattended automatic operation of the minisodar has shown its capability for all kinds of precipitation measurements. The retrieval of precipitation rates for snow and graupel will be provided in a subsequent paper

A Trouble with Ho\v{r}ava-Lifshitz Gravity

We study the structure of the phase space in Ho\v{r}ava-Lifshitz theory. With the constraints derived from the action, the phase space is described by five fields, thus there is a lack of canonical structure. The Poisson brackets of the Hamiltonian density do not form a closed structure, resulting in many new constraints. Taking these new constraints into account, it appears that there is no degree of freedom left, or the phase space is reduced to one with an odd number of fields.Comment: 12 pages, some discussions, comments and references added, JHEP styl

Convergent finite difference schemes for stochastic transport equations

We present difference schemes for stochastic transport equations with low-regularity velocity fields. We establish $L^2$ stability and convergence of the difference approximations under conditions that are less strict than those required for deterministic transport equations. The $L^2$ estimate, crucial for the analysis, is obtained through a discrete duality argument and a comprehensive examination of a class of backward parabolic difference schemes

AdS and Lifshitz Black Holes in Conformal and Einstein-Weyl Gravities

We study black hole solutions in extended gravities with higher-order curvature terms, including conformal and Einstein-Weyl gravities. In addition to the usual AdS vacuum, the theories admit Lifshitz and Schr\"odinger vacua. The AdS black hole in conformal gravity contains an additional parameter over and above the mass, which may be interpreted as a massive spin-2 hair. By considering the first law of thermodynamics, we find that it is necessary to introduce an associated additional intensive/extensive pair of thermodynamic quantities. We also obtain new Liftshitz black holes in conformal gravity and study their thermodynamics. We use a numerical approach to demonstrate that AdS black holes beyond the Schwarzschild-AdS solution exist in Einstein-Weyl gravity. We also demonstrate the existence of asymptotically Lifshitz black holes in Einstein-Weyl gravity. The Lifshitz black holes arise at the boundary of the parameter ranges for the AdS black holes. Outside the range, the solutions develop naked singularities. The asymptotically AdS and Lifshitz black holes provide an interesting phase transition, in the corresponding boundary field theory, from a relativistic Lorentzian system to a non-relativistic Lifshitz system.Comment: typos corrected, references adde

Partisipasi Kelompok Perempuan Peduli Lingkungan dalam Penanganan Sampah di Sub DAS Cikapundung Jawa Barat

Pengelolaan sampah membutuhkan dukungan dari masyarakat. Isu tentang sampah juga di temukan di Sub DAS Cikapundung. Isu lingkungan di Cikapundung Sub DAS telah mengundang perempuan untuk berpartisipasi dalam bentuk gerakan kelompok. Partisipasi masyarakat dalam pengelolaan sampah sangat penting. Penelitian ini bertujuan untuk: (1) mengidentifikasi karakteristik kelompok dan (2) menganalisis faktor-faktor yang mempengaruhi upaya ibu rumah tangga dalam menjaga gerakan kelompok peduli lingkungan di Sub DAS Cikapundung. Penelitian dilakukan dari bulan Maret hingga April 2015 yang melibatkan 106 responden dari kelompok perempuan peduli lingkungan. Kelompok-kelompok yang terletak di tiga wilayah: Sunten Jaya Desa (hulu DAS), Lebak Siliwangi Desa (tengah DAS) dan Dayeuh Kolot Desa (hilir DAS). Wawancara menggunakan kuesioner, wawancara mendalam, observasi, dan diskusi kelompok yang digunakan untuk mengumpulkan data. Korelasi Rank-Spearman digunakan untuk menguji tingkat korelasi antara variabel-variabel berikut: a) profil dan dinamika kelompok, b) dukungan keluarga, c) persepsi dan partisipasi kelompok wanita peduli lingkungan. Hasil penelitian menunjukkan bahwa kemauan, dan kemampuan kelompok wanita untuk mengolah limbah adalah faktor yang meningkatkan partisipasi. Mayoritas wanita tidak memiliki kesempatan yang sama untuk berpartisipasi dalam kelompok peduli lingkungan. Faktor yang signifikan dengan tingkat persepsi dan partisipasi wanita dalam kelompok peduli lingkungan adalah profil dan dinamika kelompok, dukungan keluarga, dukungan tokoh masyarakat dan program penyuluhan

Conformal Gravity and Extensions of Critical Gravity

Higher-order curvature corrections involving the conformally-invariant Weyl-squared action have played a role in two recent investigations of four-dimensional gravity; in critical gravity, where it is added to the standard cosmological Einstein-Hilbert action with a coefficient tuned to make the massive ghostlike spin-2 excitations massless, and in a pure Weyl-squared action considered by Maldacena, where the massive spin-2 modes are removed by the imposition of boundary conditions. We exhibit the connections between the two approaches, and we also generalise critical gravity to a wider class of Weyl-squared modifications to cosmological Einstein gravity where one can eliminate the massive ghostlike spin-2 modes by means of boundary conditions. The cosmological constant plays a crucial role in the discussion, since there is then a "window" of negative mass-squared spin-2 modes around AdS_4 that are not tachyonic. We also construct analogous conformal and non-conformal gravities in six dimensions.Comment: Latex, 20 pages, typos in (4.21) and (A.7) were correcte

Influence of regional precipitation patterns on stable isotopes in ice cores from the central Himalayas

Several ice cores have been recovered from the Dasuopu (DSP) Glacier and the East Rongbuk (ER) Glacier in the central Himalayas since the 1990s. Although the distance between the DSP and the ER ice core drilling sites is only 125 km, the stable isotopic record (18O or D) of the DSP core is interpreted in previous studies as a temperature proxy, while the ER core is interpreted as a precipitation proxy. Thus, the climatological significance of the stable isotopic records of these Himalayan ice cores remains a subject of debate. Based on analysis of regional precipitation patterns over the region, we find that remarkable discrepancy in precipitation seasonality between the two sites may account for their disparate isotopic interpretations. At the ER core site, the Indian summer monsoon (ISM) precipitation is dominating due to topographic blocking of the moisture from westerlies by the high ridges of Mt. Qomolangma (Everest), which results in a negative correlation between the ER 18O or D record and precipitation amount along the southern slope of the central Himalayas in response to the “amount effect”. At the DSP core site, in comparison with the ISM precipitation, the wintertime precipitation associated with the westerlies is likely more important owing to its local favorable topographic conditions for interacting with the western disturbances. Therefore, the DSP stable isotopic record may be primarily controlled by the westerlies. Our results have important implications for interpreting the stable isotopic ice core records recovered from different climatological regimes of the Himalayas