Characteristics of gravity waves generated in a convective and a non-convective environment revealed from hourly radiosonde observation under CPEA-II campaign

Analyses of hourly radiosonde data of temperature, wind, and relative humidity during four days (two with convection and two with no convection) as a part of an intensive observation period in CPEA-2 campaign over Koto Tabang (100.32° E, 0.20° S), Indonesia, are presented. Characteristics of gravity waves in terms of dominant wave frequencies at different heights and their vertical wavelengths are shown in the lower stratosphere during a convective and non-convective period. Gravity waves with periods ~10 h and ~4–5 h were found dominant near tropopause (a region of high stability) on all days of observation. Vertical propagation of gravity waves were seen modified near heights of the three identified strong wind shears (at ~16, 20, and 25 km heights) due to wave-mean flow interaction. Between 17 and 21 km heights, meridional wind fluctuations dominated over zonal wind, whereas from 22 to 30 km heights, wave fluctuations with periods ~3–5 h and ~8–10 h in zonal wind and temperature were highly associated, suggesting zonal orientation of wave propagation. Gravity waves from tropopause region to 30 km heights were analyzed. In general, vertical wavelength of 2–5 km dominated in all the mean-removed (~ weekly mean) wind and temperature hourly profiles. Computed vertical wavelength spectra are similar, in most of the cases, to the source spectra (1–16 km height) except that of zonal wind spectra, which is broad during active convection. Interestingly, during and after convection, gravity waves with short vertical wavelength (~2 km) and short period (~2–3 h) emerged, which were confined in the close vicinity of tropopause, and were not identified on non-convective days, suggesting convection to be the source for them. Some wave features near strong wind shear (at 25 km height) were also observed with short vertical wavelengths in both convective and non-convective days, suggesting wind shear to be the sole cause of generation and seemingly not associated with deep convection below. A drop in the temperature up to ~4–5 K (after removal of diurnal component) was observed at ~16 km height near a strong wind shear (~45–55 m s⁻¹ km⁻¹) during active period of convection

The Horizontal Component of Photospheric Plasma Flows During the Emergence of Active Regions on the Sun

The dynamics of horizontal plasma flows during the first hours of the emergence of active region magnetic flux in the solar photosphere have been analyzed using SOHO/MDI data. Four active regions emerging near the solar limb have been considered. It has been found that extended regions of Doppler velocities with different signs are formed in the first hours of the magnetic flux emergence in the horizontal velocity field. The flows observed are directly connected with the emerging magnetic flux; they form at the beginning of the emergence of active regions and are present for a few hours. The Doppler velocities of flows observed increase gradually and reach their peak values 4-12 hours after the start of the magnetic flux emergence. The peak values of the mean (inside the +/-500 m/s isolines) and maximum Doppler velocities are 800-970 m/s and 1410-1700 m/s, respectively. The Doppler velocities observed substantially exceed the separation velocities of the photospheric magnetic flux outer boundaries. The asymmetry was detected between velocity structures of leading and following polarities. Doppler velocity structures located in a region of leading magnetic polarity are more powerful and exist longer than those in regions of following polarity. The Doppler velocity asymmetry between the velocity structures of opposite sign reaches its peak values soon after the emergence begins and then gradually drops within 7-12 hours. The peak values of asymmetry for the mean and maximal Doppler velocities reach 240-460 m/s and 710-940 m/s, respectively. An interpretation of the observable flow of photospheric plasma is given.Comment: 20 pages, 10 figures, 3 tables. The results of article were presented at the ESPM-13 (12-16 September 2011, Rhodes, Greece, Abstract Book p. 102, P.4.12, http://astro.academyofathens.gr/espm13/documents/ESPM13_abstract_programme_book.pdf

Spectro-Polarimetric Observation of an Emerging Flux Region: Triggering Mechanism of Ellerman Bombs

High spatial resolution observation of an emerging flux region (EFR) was done using a vector magnetograph and a H-alpha Lyot filtergraph with Domeless Solar Telescope at Hida Observatory on October 22, 2006. In H-alpha wing images, we could see many Ellerman bombs (EBs) in the EFR. Two observation modes, slit scan and slit fixed, were performed with the vector magnetograph, along with H-alpha filtergraph. Using H-alpha wing images, we detected 12 EBs during slit scan observation period and 9 EBs during slit fixed observation period. With slit scan observation, we found that all the EBs were distributed in the area where the spatial gradient of vertical field intensity was large, which indicates the possibility of rapid topological change in magnetic field in the area of EBs. With slit fixed observation, we found that EBs were distributed in the areas of undulatory magnetic fields, both in vertical and horizontal components. This paper is the first to report the undulatory pattern in horizontal components of magnetic field, which is also evidence for emerging magnetic flux by Parker instability. These results allow us to confirm the association between EBs and emerging flux tubes. Three triggering mechanism of EBs is discussed with respect to emerging flux tubes: 9 out of 21 EBs occurred at the footpoints of emerging flux tubes, 8 out of 21 EBs occurred at the top of emerging flux tubes, and 4 out of 21 EBs occurred at unipolar region. Each case can be explained by magnetic reconnection in the low chromosphere.Comment: 30 pages, 17 figure

Planar shock wave generated by uniform irradiation from two overlapped partially coherent laser beams

Copyright 2001 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 89(5), 2571-2575, 2001 and may be found at http://dx.doi.org/10.1063/1.134218

Stevens-Johnson syndrome and toxic epidermal necrolysis in childhood-onset systemic lupus erythematosus patients: a multicenter study

Objective: To assess Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in a large population of childhood-onset systemic lupus erythematosus (cSLE) patients. Methods: Multicenter study including 852 cSLE patients followed in Pediatric Rheumatology centers in Sao Paulo, Brazil. SJS was defined as epidermal detachment below 10% of body surface area (BSA), overlap SJS-TEN 10-30% and TEN greater than 30% of BSA. Results: SJS and TEN were observed in 5/852 (0.6%) cSLE female patients, three patients were classified as SJS and two patients were classified as overlap SJS-TENTEN was not observed. The mean duration of SJS and overlap SJS-TEN was 15 days (range 7-22) and antibio tics induced four cases. Regarding extra-cutaneous manifestations, hepatomegaly was observed in two cSLE patients, nephritis in two and neuropsychiatric involvement and conjunctivitis were observed respectively in one patient. Hematological involvement included lymphopenia in four, leucopenia in three and thrombocytopenia in two patients. The mean SLEDAI-2K score was 14.8 (range 6-30). Laboratory analysis showed low C3, C4 and/or CH50 in two patients and the presence of anti-dsDNA autoantibody in two patients. One patient had lupus anticoagulant and another one had anticardiolipin IgG. All patients were treated with steroids and four needed additional treatment such as intravenous immunoglobulin in two patients, hydroxychloroquine and azathioprine in two and intravenous cyclophosphamide in one patient. Sepsis was observed in three cSLE patients. Two patients required intensive care and death was observed in one patient. Conclusion: Our study identified SJS and overlap SJS-TEN as rare manifestations of active cSLE associated with severe multisystemic disease, with potentially lethal outcome.Conselho Nacional de Desenvolvimento Cientifico e TecnologicoFederico FoundationNucleo de Apoio a Pesquisa "Saude da Crianca e do Adolescente" of USP (NAP-CriAd)Univ Fed Sao Paulo, Pediat Rheumatol Unit, Sao Paulo, SP, BrazilUniv Sao Paulo, Pediat Rheumatol Unit, Fac Med, Sao Paulo, BrazilUniv Sao Paulo, Div Rheumatol, Fac Med, Sao Paulo, BrazilSao Paulo State Univ UNESP, Fac Med Botucatu, Pediat Rheumatol Div, Botucatu, SP, BrazilHosp Infantil Darcy Vargas, Pediat Rheumatol Unit, Sao Paulo, BrazilUniv Fed Sao Paulo, Pediat Rheumatol Unit, Sao Paulo, SP, BrazilCNPq: 303422/2015-7CNPq: 301805/2013-0CNPq: 305068/2014-8CNPq: 301479/2015CNPq: 303752/2015-7Federico FoundationNAP-CriAd-USPWeb of Scienc

Dioxin Toxicity In Vivo Results from an Increase in the Dioxin-Independent Transcriptional Activity of the Aryl Hydrocarbon Receptor

The Aryl hydrocarbon receptor (Ahr) is the nuclear receptor mediating the toxicity of dioxins -widespread and persistent pollutants whose toxic effects include tumor promotion, teratogenesis, wasting syndrome and chloracne. Elimination of Ahr in mice eliminates dioxin toxicity but also produces adverse effects, some seemingly unrelated to dioxin. Thus the relationship between the toxic and dioxin-independent functions of Ahr is not clear, which hampers understanding and treatment of dioxin toxicity. Here we develop a Drosophila model to show that dioxin actually increases the in vivo dioxin-independent activity of Ahr. This hyperactivation resembles the effects caused by an increase in the amount of its dimerisation partner Ahr nuclear translocator (Arnt) and entails an increased transcriptional potency of Ahr, in addition to the previously described effect on nuclear translocation. Thus the two apparently different functions of Ahr, dioxin-mediated and dioxin-independent, are in fact two different levels (hyperactivated and basal, respectively) of a single function