Properties of arctic haze aerosol from lidar observations during iarea 2015 campaign on spitsbergen

Arctic Haze event was observed on 5-8 April 2015 using simultaneously Near-range Aerosol Raman Lidar of IGFUW and Koldewey Aerosol Raman Lidar of AWI, both based at AWIPEV German-French station in Ny-Ålesund, Spitsbergen. The alterations in particle abundance and altitude of the aerosol load observed on following days of the event is analyzed. The daytime profiles of particle optical properties were obtained for both lidars, and then served as input for microphysical parameters inversion. The results indicate aerosol composition typical for the Arctic Haze. However, in some layers, a likely abundance of aqueous aerosol or black carbon originating in biomass burning over Siberia, changes measurably the Arctic Haze properties

Risk factors of permanent hypoparathyroidism after total thyroidectomy and central neck dissection for papillary thyroid cancer: a prospective study

Introduction: Inadvertent removal of, or damage to the parathyroid glands in the course of operations on the anterior neck compartment are responsible for over 80% of cases of chronic hypoparathyroidism (HypoPT). This study searched for factors related to the development of permanent HypoPT after total thyroidectomy and central neck lymphadenectomy in patients with thyroid carcinoma. Material and methods: In total, 89 of 103 screened patients met the study’s criteria and were put under prospective one-year observation. Demographic and surgical factors as well as the biochemical parameters of mineral homeostasis, controlled both preoperatively and postoperatively, were subject to statistical analysis. In line with contemporary guidelines, postoperative hypocalcaemia, rather than an abnormally low serum parathormone (PTH) concentration, was considered a diagnostic criterion of HypoPT. Results: On postoperative day one (POD1), serum concentration of PTH decreased below the normal range (< 12 pg/mL) in 29 patients and was undetectable in 19 patients (< 6 pg/mL). At one year postoperatively, 12 patients with undetectable POD1 PTH required treatment for hypocalcaemia and were diagnosed with permanent hypoPT. All the other patients regained normocalcaemia. Relative risk of permanent HypoPT associated with undetectable POD1 PTH was 88.75. A significant difference in median POD1 serum calcium concentration between the patients with undetectable POD1 PTH and those with detectable POD1 PTH was found (p < 0.001). The difference between the POD1 serum calcium in patients with permanent or transient HypoPT in the subgroup with undetectable POD1 PTH did not reach the level of statistical significance (median, 1.82 mmol/L vs. 1.96 mmol/L). At one month postoperatively, in patients who later developed permanent HypoPT, serum calcium was lower than it was in all other patients (p = 0.167). At one year postoperatively, serum concentration of PTH was in the normal range in 10 of 12 patients with permanent HypoPT; however, it was significantly lower than it had been before the operation and distinctly lower than it was in patients who regained normocalcaemia. The number of parathyroid glands either dissected or autotransplanted did not affect the development of permanent HypoPT. Conclusions: Undetectable POD1 PTH is an important risk factor of permanent HypoPT. The main cause of permanent HypoPT was irreversible damage to the left in situ parathyroid glands

Variability of the boundary layer over an urban continental site based on 10 years of active remote sensing observations in Warsaw

Atmospheric boundary layer height (ABLH) was observed by the CHM15k ceilometer (January 2008 to October 2013) and the PollyXT lidar (July 2013 to December 2018) over the European Aerosol Research LIdar NETwork to Establish an Aerosol Climatology (EARLINET) site at the Remote Sensing Laboratory (RS-Lab) in Warsaw, Poland. Out of a maximum number of 4017 observational days within this period, a subset of quasi-continuous measurements conducted with these instruments at the same wavelength (1064 nm) was carefully chosen. This provided a data sample of 1841 diurnal cycle ABLH observations. The ABLHs were derived from ceilometer and lidar signals using the wavelet covariance transform method (WCT), gradient method (GDT), and standard deviation method (STD). For comparisons, the rawinsondes of the World Meteorological Organization (WMO 12374 site in Legionowo, 25 km distance to the RS-Lab) were used. The ABLHs derived from rawinsondes by the skew-T-log-p method and the bulk Richardson (bulk-Ri) method had a linear correlation coefficient (R2) of 0.9 and standard deviation (SD) of 0.32 km. A comparison of the ABLHs obtained for different methods and instruments indicated a relatively good agreement. The ABLHs estimated from the rawinsondes with the bulk-Ri method had the highest correlations, R2 of 0.80 and 0.70 with the ABLHs determined using the WCT method on ceilometer and lidar signals, respectively. The three methods applied to the simultaneous, collocated lidar, and ceilometer observations (July to October 2013) showed good agreement, especially for the WCT method (R2 of 0.94, SD of 0.19 km). A scaling threshold-based algorithm was proposed to homogenize ceilometer and lidar datasets, which were applied on the lidar data, and significantly improved the coherence of the results (R2 of 0.98, SD of 0.11 km). The difference of ABLH between clear-sky and cloudy conditions was on average below 230 m for the ceilometer and below 70 m for the lidar retrievals. The statistical analysis of the long-term observations indicated that the monthly mean ABLHs varied throughout the year between 0.6 and 1.8 km. The seasonal mean ABLH was of 1.16 ± 0.16 km in spring, 1.34 ± 0.15 km in summer, 0.99 ± 0.11 km in autumn, and 0.73 ± 0.08 km in winter. In spring and summer, the daytime and nighttime ABLHs appeared mainly in a frequency distribution range of 0.6 to 1.0 km. In winter, the distribution was common between 0.2 and 0.6 km. In autumn, it was relatively balanced between 0.2 and 1.2 km. The annual mean ABLHs maintained between 0.77 and 1.16 km, whereby the mean heights of the well-mixed, residual, and nocturnal layer were 1.14 ± 0.11, 1.27 ± 0.09, and 0.71 ± 0.06 km, respectively (for clear-sky conditions). For the whole observation period, the ABLHs below 1 km constituted more than 60% of the retrievals. A strong seasonal change of the monthly mean ABLH diurnal cycle was evident; a mild weakly defined autumn diurnal cycle, followed by a somewhat flat winter diurnal cycle, then a sharp transition to a spring diurnal cycle, and a high bell-like summer diurnal cycle. A prolonged summertime was manifested by the September cycle being more similar to the summer than autumn cycles

Lidar Measurements of Canadian Forest Fire Smoke Episode Observed in July 2013 over Warsaw, Poland

This paper presents a preliminary study of aerosol optical properties of air-mass advected on 10th July 2013 from Canada above Warsaw, Poland, during the forest fire event that occurred in Quebec at the beginning of July 2013. The observations were conducted with use of the modern version of 8-channel PollyXT lidar capable of measuring at 3β+2α+2δ+VW and interpreted with available information from the MACC model, the CALIPSO and MODIS satellite sensors, the AERONET data products and the data gathered within the Poland-AOD network

Real-time ultrasound elastography - a new tool for diagnosing thyroid nodules

Introduction: Real-time elastography (RTE) is a non-invasive ultrasound method of estimation of tissue stiffness by measuring the degree of local tissue displacements after a small compression. Recent data has shown its ability to differentiate benign from malignant tumours. The aim of this study was to evaluate the accuracy of RTE in the diagnosis of malignant and benign thyroid nodules. Material and methods: 71 thyroid nodules in 52 patients: 42 females and 10 males aged 28-77 were examined using conventional ultrasonography (US), fine-flow CD imaging and RTE. All nodules previously underwent fine-needle aspiration biopsy (FNAB), and patients with malignant and suspicious cytological results were referred for surgery. The final diagnosis was based on FNAB results in patients with benign cytology and on the histopathology reading in those who underwent surgery. An elasticity score (ES) from 1 to 5 was determined for each nodule according to the Ueno classification. Results: An elasticity score (ES) of 4 or 5 was found in 19 out of 22 (86.5%) thyroid cancers and in only 1 out of 31 (3%) benign nodules. This was strongly indicative for malignancy (p < 0.0001) with sensitivity 86%, specificity 97%, positive predictive value (PPV) 95% and negative predictive value (NPV) 91%. Conclusions: RTE is a highly sensitive and specific method of diagnosing thyroid nodules. This technique can be employed in selecting thyroid nodules for fine-needle aspiration biopsy. (Pol J Endocrinol 2010; 61 (6): 652-657)Wstęp: Elastografia czasu rzeczywistego (RTE, real-time elastography) jest nieinwazyjną metodą oceny twardości tkanki poprzez pomiar stopnia lokalnych przemieszczeń tkankowych pod wpływem słabego ucisku. Ostatnie dane wskazują na jej zdolność do różnicowania guzów łagodnych i złośliwych. Celem pracy była ocena dokładności diagnostycznej RTE w rozpoznawaniu złośliwych i łagodnych guzów tarczycy. Materiał i metody: Siedemdziesiąt jeden zmian ogniskowych tarczycy u 52 pacjentów: 42 kobiet i 10 mężczyzn w wieku 28-77 lat poddano badaniu ultrasonograficznemu w skali szarości, ocenie przepływów metodą fine-flow CD i RTE. Wszystkie zmiany były uprzednio poddane biopsji aspiracyjnej cienkoigłowej (BAC), a pacjenci z cytologicznym rozpoznaniem zmiany złośliwej lub podejrzanej byli kierowani do leczenia operacyjnego. Rozpoznanie ostateczne u pacjentów z cytologicznie stwierdzoną zmianą łagodną ustalono na podstawie wyniku BAC, zaś u poddanych operacji na podstawie wyniku badania histopatologicznego. Dla każdej zmiany oceniano wskaźnik elastyczności (ES) w skali od 1 do 5 zgodnie z klasyfikacją Ueno. Wyniki: Wskaźnik elastyczności 4 lub 5 stwierdzono w 19/22 (86,5%) raków tarczycy i tylko w 1/31 (3%) łagodnej zmianie ogniskowej. Wskazywał on silnie na złośliwość zmiany (p < 0,0001) z czułością 86%, swoistością 97%, dodatnią wartością predykcyjną 95% i ujemną wartością predykcyjną 91%. Wnioski: Elastografia czasu rzeczywistego jest wysoce czułą i swoistą metodą w diagnostyce zmian ogniskowych tarczycy. Technika ta może być stosowana do typowania zmian ogniskowych tarczycy wymagających biopsji aspiracyjnej cienkoigłowej. (Endokrynol Pol 2010; 61 (6): 652-657

First Ever Observations of Mineral Dust in Wintertime over Warsaw, Poland

The long-range transport of desert dust over the area of the temperate climate zone is associated with the influx of hot air masses due to the location of the sources of this aerosol in the tropical climate zone. Between 24–26 February 2021, such an aerosol outbreak took place and reached Central Europe. The mean temperature of +11.7 °C was recorded during the event. A comparison of this value to the 20-year (2000–2020) average February temperature for Warsaw (−0.2 °C) indicates the uniqueness of the meteorological conditions. It was the first wintertime inflow of Saharan dust over Warsaw, the presence of which was confirmed by lidar and sun-photometer measurements. The properties of the desert dust layers were obtained; the mean values of the particle depolarization for the fully developed mineral dust layer were 13 ± 3% and 22 ± 4% for 355 and 532 nm, respectively. The aerosol optical thickness was high with average values >0.36 for all wavelengths smaller than 500 nm. The three-modal, aerosol size distribution was dominated by coarse-mode particles, with a visible contribution of accumulation-mode particles. It suggests the possible presence of other aerosol types

Study case of air-mass modification over Poland and Romania observed by the means of multiwavelength Raman depolarization lidars

An air-mass modification, on its way from Poland to Romania, observed between 19-21 July 2014 is discussed. The air-mass was investigated using data of two multi-wavelength lidars capable of performing regular elastic, depolarization and Raman measurements in Warsaw, Poland, and in Magurele, Romania. The analysis was focused on evaluating optical properties of aerosol in order to search for similarities and differences in the vertical profiles describing the atmospheric layers above the two stations within given period

Near-range receiver unit of next generation PollyXT used with Koldeway aerosol Raman lidar in Arctic

The Near-range Aerosol Raman lidar (NARLa) receiver unit, that was designed to enhance the detection range of the NeXT generation PollyXT Aerosol-Depolarization-Raman (ADR) lidar of the University of Warsaw, was employed next the Koldeway Aerosol Raman Lidar (KARL) at the AWI-IPEV German-French station in Arctic during Spring 2015. Here we introduce shortly design of both lidars, the scheme of their installation next to each other, and preliminary results of observations aiming at arctic haze investigation by the lidars and the iCAP a set of particle counter and aethalometer installed under a tethered balloon

Spatio-temporal evolution of long-range transported mineral desert dust properties over rural and urban sites in Central Europe

An exceptionally strong and very fast (120h) mineral dust inflow from North Africa to Poland was predicted by NMMB/BSC-Dust and NAAPS models on 10–11 June 2019. Simultaneous measurements with two complex lidar systems at the EARLINET-ACTRIS urban site in Warsaw (Central Poland) and the PolWET peatland site in Rzecin (Western Poland) captured the evolution of this dust event. The advected air masses had different source areas in North Africa, they were reaching each station via independent pathways, and thus, were unlikely mixed with each other. The excellent capabilities of the next generation PollyXT lidar and the mobile EMORAL lidar allowed for the derivation of full datasets of aerosol optical properties profiles that enabled comparative study of the advected dust properties evolution. Within a mere 350 km distance between Warsaw and Rzecin, distinctly different dust properties were measured, respectively: dry mineral dust composed mainly of coarse mode dust particles (50 ± 5 % of the total particle backscattering profile) versus the wet mineral dust dominated by fine dust particles (58 ± 4 %). A new parameter fine-to-coarse dust ratio (FCDR) is proposed to describe more intuitively mineral dust composition