399 research outputs found
Surface cyclone mask for the Antarctic Circumnavigation Expedition from December 2016 – March 2017.
No full textDataset abstract
This dataset contains a surface cyclone mask, which records the presence of a surface cyclone along the track of the Antarctic Circumnavigation expedition (ACE). The surface cyclones are calculated applying a 2D cyclone identification algorithm (Wernli and Schwierz, 2006; Sprenger et al., 2017) using global operational analysis data of the European Centre for Medium Range Weather Forecasts.
Dataset contents
- cyclone_mask_1h.csv, data file, comma-separated values
- data_file_header.txt, metadata, text
- README.txt, metadata, text
Dataset license
This surface cyclone mask dataset from ACE is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full text can be found at https://creativecommons.org/licenses/by/4.0/The Antarctic Circumnavigation Expedition was made possible by funding from the Swiss Polar Institute and Ferring Pharmaceuticals
Saharan rainfall climatology and its relationship with surface cyclones
Full text linkThe Sahara is the largest and driest of the hot deserts on Earth, with regions where rainfall reaches the surface on average less than once a year. Water resources are scarce, and rainfall tends to occur sporadically in space and time. While rain is a precious resource in the Sahara, heavy precipitation events (HPEs) in the desert have the potential to trigger flash floods on the barren soil. Because of the sparse rainfall monitoring network and the relatively poor performance of global models in representing rainfall over the Sahara, the analysis of Saharan HPEs has primarily relied on case studies. Therefore, general rainfall characteristics of Saharan HPEs are unexplored, and the prevailing weather conditions enabling such rainfall are unknown. To tackle this problem, we utilised satellite-derived precipitation estimations (IMERG) spanning 21 years (2000–2021) to identify ∼42⋅103 small (>103km2) to large (<106km2) HPEs in the Sahara and to extract their rainfall properties, and atmospheric reanalyses (ERA5) to examine the corresponding meteorological conditions in which they develop. Three case studies illustrate the relevance of cyclones for exceptionally large HPEs, including one in the driest region of the Sahara. Saharan HPEs occur, on average, every second day. They are more common in summer than in the other seasons, occur most frequently in the southern Sahara, and exhibit a clear convectively-driven diurnal cycle. Winter events have, on average, larger spatial extent, longer duration, and are characterised by larger areas exhibiting more extreme rainfall in terms of return periods. Autumn HPEs are concentrated in the western Sahara, while events in the north of the desert and in its driest core in the northeast occur mainly in winter and spring. In these regions, north of the Tropic of Cancer, events are highly associated with surface cyclones. HPEs that were associated with cyclones are characterised by larger spatial extent and rainfall volume. Considering that weather and climate models often depict synoptic-scale weather systems more accurately than rainfall patterns, the association of Saharan HPEs with surface cyclones and other synoptic-scale systems can aid in comprehending the effects of climate change in the desert. Furthermore, it underscores the potential for higher predictability of these events
A Trajectory-Based Investigation of Physical and Dynamical Processes That Govern the Temporal Evolution of the Subtropical Jet Streams over Africa
Full text linkVauvan oma vihko - keino vahvistaa vauvan ja vanhemman välistä suhdetta lastenosastolla
Full text linkOpinnäytetyön tavoitteena oli tuottaa vauvakirjamainen vihko Päijät-Hämeen keskus-sairaalan osasto 13:n käyttöön. Osastolla hoidetaan vastasyntyneitä, jotka jostain syystä tarvitsevat lääketieteellistä apua elämänsä ensimetreillä. Vauvojen vanhemmat voivat kerätä vihkoon muistoja osastoajalta sekä kirjata ylös lapsensa kehittymisen välietappeja. Vihkoon voi liimata myös kuvia. Vihkon laajuus on 14 sivua, ja se on suunniteltu yhdessä toimeksiantajan kanssa.
Vihkon tarkoitus on tukea osaston jokapäiväistä hoitotyötä ja osastolla käytettävää Vanhemmat vahvasti mukaan (VVM) -toimintamallia. Vihko auttaa sitouttamaan vanhempia entistä vahvemmin vauvansa hoitamiseen ja opettaa heitä tuntemaan vauvansa entistä paremmin. Sen tarkoitus on olla yksi VVM:n suositteleman perhelähtöisen kotiutussuunnittelun työvälineistä.
Opinnäytetyö pitää sisällään teoreettisen viitekehyksen sekä toiminnallisen osuuden eli vihkosen toteuttamisen. Teoreettisessa viitekehyksessä käydään läpi muun muassa erityistarpeisen vauvan perhelähtöistä hoitotyötä sekä varhaisen sairaalahoidon vaikutuksia perheeseen ja kiintymyssuhteisiin. Toiminnallisen osuuden raportoinnissa selitetään vihkosen suunnittelun vaiheet sekä yhteistyöprosessi tilaajan kanssa.The aim of the thesis was to create a booklet for the parents of a newborn that is taken into the Neonatal intensive care and Observation (NICU) Ward of Päijät-Häme Central Hospital. There can be many reasons for a newborn to need special medical care. He or she might have been born premature or have some illnesses that need acute intervention. In this booklet parents can collect memories from the time they spend in the ward and fill in the development of their baby. Parents can also add pictures to the booklet.
The purpose of this thesis is to support the everyday care work on the ward and to be part of the Vanhemmat Vahvasti mukaan -model’s nursing. Baby’s own booklet will engage parents in the nursing of their baby and help them acknowledge that they have the skills to listen to their baby’s needs. The booklet will also support family centered care and family-oriented discharge from the hospital.
This thesis includes a report and the booklet. The report contains the theoretical background and the description of the thesis process. The most commonly used phrases will be explained in the theoretical part. The booklet includes 14 pages and it was developed in co-operation with Päijät-Häme Central Hospital. The booklet was assembled independently by the author and edited according to the feedback given by NICU’s nurses
Northern Hemisphere Rossby Wave Initiation Events on the Extratropical Jet—A Climatological Analysis
Full text linkA climatology of Rossby wave initiation (RWI) events on the Northern Hemisphere midlatitude jet is
compiled by applying an objective RWI identification algorithm to the ERA-Interim dataset. In winter, RWI
events occur most frequently over the northwestern Pacific and less often over the North Atlantic. In summer, the total number of RWI events is lower than in winter and the North Pacific RWI region shifts toward the Tibetan Plateau. Composite analysis of the large-scale flow prior to, during, and after winter North Pacific RWI events shows an upstream wave train propagating across Asia on the Arctic waveguide prior to RWI. The composite wave forms on a relatively weak zonal jet streak, exhibits a baroclinic structure, and is strongly amplified by latent heat release in the warm conveyor belt of a deepening surface cyclone. Moreover, the wave forms in a region of large-scale upper-level deformation, upstream of a preexisting ridge. Further, active tropical convection affects the longitude where RWI occurs and thus acts as a geographical anchor for RWI. Individual RWI events are characterized by preferred combinations of these composite features: a strong surface cyclone tends to occur in concert with strong latent heating and a pronounced positive PV anomaly aloft. A second group of co-occurring features contains active tropical convection, a strengthened subtropical anticyclone, and the downstream ridge. These feature groups might be regarded as idealized archetypal RWI scenarios, although numerous intermediate events exist where features from both groups occur together
An algorithm for identifying the initiation of synoptic-scale Rossby waves on potential vorticity waveguides
Full text linkLagrangian matches between observations from aircraft, lidar and radar in an orographic warm conveyor belt
Full text linkWarm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation and the amplification of upper-level ridges. This study presents a case study that involves aircraft, lidar and radar observations in a WCB ascending from western Europe towards the Baltic Sea during the field experiments HyMeX and T-NAWDEX-Falcon in October 2012.
Trajectories were used to link different observations along the WCB, that is to establish so-called Lagrangian matches between observations. To this aim, wind fields of the ECMWF ensemble data assimilation system were used, which allowed for a probabilistic quantification of the WCB occurrence and the Lagrangian matches. Despite severe air traffic limitations for performing research flights over Europe, the DLR Falcon successfully sampled WCB air masses during different phases of the WCB ascent. The WCB trajectories revealed measurements in two distinct WCB branches: one branch ascended from the eastern North Atlantic over southwestern France, while the other had its inflow in the western Mediterranean. Both branches passed across the Alps, and for both branches, Lagrangian matches coincidentally occurred between lidar water vapour measurements in the inflow of the WCB south of the Alps, radar measurements during the ascent at the Alps, and in situ aircraft measurements by Falcon in the WCB outflow north of the Alps. An airborne release experiment with an inert tracer could confirm the long pathway of the WCB from the inflow in the Mediterranean boundary layer to the outflow in the upper troposphere near the Baltic Sea several hours later.
The comparison of observations and ensemble analyses reveals a moist bias in the analyses in parts of the WCB inflow but a good agreement of cloud water species in the WCB during ascent. In between these two observations, a precipitation radar measured strongly precipitating WCB air located directly above the melting layer while ascending at the southern slopes of the Alps. The trajectories illustrate the complexity of a continental and orographically influenced WCB, which leads to (i) WCB moisture sources from both the Atlantic and Mediterranean, (ii) different pathways of WCB ascent affected by orography, and (iii) locally steep WCB ascent with high radar reflectivity values that might result in enhanced precipitation where the WCB flows over the Alps. The linkage of observational data by ensemble-based WCB trajectory calculations and confirmed by an inert tracer, and the model evaluation using the multi-platform observations are the central elements of this study and reveal important aspects of orographically modified WCBs
Radiographic and safety details of vertebral body stenting : results from a multicenter chart review
Full text linkBackground: Up to one third of BKP treated cases shows no appreciable height restoration due to loss of both restored height and kyphotic realignment after balloon deflation. This shortcoming has called for an improved method that maintains the height and realignment reached by the fully inflated balloon until stabilization of the vertebral body by PMMA-based cementation. Restoration of the physiological vertebral body height for pain relief and for preventing further fractures of adjacent and distant vertebral bodies must be the main aim for such a method. A new vertebral body stenting system (VBS) stabilizes the vertebral body after balloon deflation until cementation. The radiographic and safety results of the first 100 cases where VBS was applied are presented.
Methods: During the planning phase of an ongoing international multicenter RCT, radiographic, procedural and followup details were retrospectively transcribed from charts and xrays for developing and testing the case report forms. Radiographs were centrally assessed at the institution of the first/senior author.
Results: 100 patients (62 with osteoporosis) with a total of 103 fractured vertebral bodies were treated with the VBS system. 49 were females with a mean age of 73.2 years; males were 66.7 years old. The mean preoperative anterior-middle-posterior heights were 20.3-17.6-28.0 mm, respectively. The mean local kyphotic angle was 13.1°. The mean preoperative Beck Index (anterior edge height/posterior edge height) was 0.73, the mean alternative Beck Index (middle height/posterior edge height) was 0.63. The mean postoperative heights were restored to 24.5-24.6-30.4 mm, respectively. The mean local kyphotic angle was reduced to 8.9°. The mean postoperative Beck Index was 0.81, the mean alternative one was 0.82. The overall extrusion rate was 29.1%, the symptomatic one was 1%. In the osteoporosis subgroup there were 23.8% extrusions. Within the three months followup interval there were 9% of adjacent and 4% of remote new fractures, all in the osteoporotic group.
Conclusions: VBS showed its strengths especially in realignment of crush and biconcave fractures. Given that fracture mobility is present, the realignment potential is sound and increases with the severity of preoperative vertebral body deformation
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Transport timescales and tracer properties in the extratropical UTLS
Full text linkA comprehensive evaluation of seasonal backward trajectories initialized in the northern hemisphere lowermost stratosphere (LMS) has been performed to investigate the factors that determine the temporal and spatial structure of troposphere-to-stratosphere-transport (TST) and it’s impact on the LMS. In particular we explain the fundamental role of the transit time since last TST (tTST) for the chemical composition of the LMS. According to our results the structure of the LMS can be characterized by a layer with tTST<40 days forming a narrow band around the local tropopause. This layer extends about 30K above the local dynamical tropopause, corresponding to the extratropical tropopause transition layer (ExTL) as identified by CO. The LMS beyond this layer shows a relatively well defined separation as marked by an aprupt transition to longer tTST indicating less frequent mixing and a smaller fraction of tropospheric air. Thus the LMS constitutes a region of two well defined regimes of tropospheric influence. These can be characterized mainly by different transport times from the troposphere and different fractions of tropospheric air. Carbon monoxide (CO) mirrors this structure of tTST due to it’s finite lifetime on the order of three months. Water vapour isopleths, on the other hand, do not uniquely indicate TST and are independent of tTST, but are determined by the Lagrangian Cold Point (LCP) of air parcels. Most of the backward trajectories from the LMS experienced their LCP in the tropics and sub-tropics, and TST often occurs 20 days after trajectories have encountered their LCP. Therefore, ExTL properties deduced from CO and H2O provide totally different informations on transport and particular TST for the LMS
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