A combined Raman lidar for low tropospheric studies

One of the main goals of laser sensing of the atmosphere was the development of techniques and facilities for remote determination of atmospheric meteorological and optical parameters. Of lidar techniques known at present the Raman-lidar technique occupies a specific place. On the one hand Raman lidar returns due to scattering on different molecular species are very simple for interpretation and for extracting the information on the atmospheric parameters sought, but, on the other hand, the performance of these techniques in a lidar facility is overburdened with some serious technical difficulties due to extremely low cross sections of Raman effect. Some results of investigations into this problem is presented which enables the construction of a combined Raman lidar capable of acquiring simultaneously the profiles of atmospheric temperature, humidity, and some optical characteristics in the ground atmospheric layer up to 1 km height. The operation of this system is briefly discussed

Estimating methane emissions in the Arctic nations using surface observations from 2008 to 2019

The Arctic is a critical region in terms of global warming. Environmental changes are already progressing steadily in high northern latitudes, whereby, among other effects, a high potential for enhanced methane (CH4) emissions is induced. With CH4 being a potent greenhouse gas, additional emissions from Arctic regions may intensify global warming in the future through positive feedback. Various natural and anthropogenic sources are currently contributing to the Arctic's CH4 budget; however, the quantification of those emissions remains challenging. Assessing the amount of CH4 emissions in the Arctic and their contribution to the global budget still remains challenging. On the one hand, this is due to the difficulties in carrying out accurate measurements in such remote areas. Besides, large variations in the spatial distribution of methane sources and a poor understanding of the effects of ongoing changes in carbon decomposition, vegetation and hydrology also complicate the assessment. Therefore, the aim of this work is to reduce uncertainties in current bottom-up estimates of CH4 emissions as well as soil oxidation by implementing an inverse modelling approach in order to better quantify CH4 sources and sinks for the most recent years (2008 to 2019). More precisely, the objective is to detect occurring trends in the CH4 emissions and potential changes in seasonal emission patterns. The implementation of the inversion included footprint simulations obtained with the atmospheric transport model FLEXPART (FLEXible PARTicle dispersion model), various emission estimates from inventories and land surface models, and data on atmospheric CH4 concentrations from 41 surface observation sites in the Arctic nations. The results of the inversion showed that the majority of the CH4 sources currently present in high northern latitudes are poorly constrained by the existing observation network. Therefore, conclusions on trends and changes in the seasonal cycle could not be obtained for the corresponding CH4 sectors. Only CH4 fluxes from wetlands are adequately constrained, predominantly in North America. Within the period under study, wetland emissions show a slight negative trend in North America and a slight positive trend in East Eurasia. Overall, the estimated CH4 emissions are lower compared to the bottom-up estimates but higher than similar results from global inversions.</p

Overview: Recent advances in the understanding of the northern Eurasian environments and of the urban air quality in China – a Pan-Eurasian Experiment (PEEX) programme perspective

The Pan-Eurasian Experiment (PEEX) Science Plan, released in 2015, addressed a need for a holistic system understanding and outlined the most urgent research needs for the rapidly changing Arctic-boreal region. Air quality in China, together with the long-range transport of atmospheric pollutants, was also indicated as one of the most crucial topics of the research agenda. These two geographical regions, the northern Eurasian Arctic-boreal region and China, especially the megacities in China, were identified as a “PEEX region”. It is also important to recognize that the PEEX geographical region is an area where science-based policy actions would have significant impacts on the global climate. This paper summarizes results obtained during the last 5 years in the northern Eurasian region, together with recent observations of the air quality in the urban environments in China, in the context of the PEEX programme. The main regions of interest are the Russian Arctic, northern Eurasian boreal forests (Siberia) and peatlands, and the megacities in China. We frame our analysis against research themes introduced in the PEEX Science Plan in 2015. We summarize recent progress towards an enhanced holistic understanding of the land–atmosphere–ocean systems feedbacks. We conclude that although the scientific knowledge in these regions has increased, the new results are in many cases insufficient, and there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures, especially the lack of coordinated, continuous and comprehensive in situ observations of the study region as well as integrative data analyses, hindering a comprehensive system analysis. The fast-changing environment and ecosystem changes driven by climate change, socio-economic activities like the China Silk Road Initiative, and the global trends like urbanization further complicate such analyses. We recognize new topics with an increasing importance in the near future, especially “the enhancing biological sequestration capacity of greenhouse gases into forests and soils to mitigate climate change” and the “socio-economic development to tackle air quality issues”

Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region

The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context

Neurohumoral relationship in patients with rheumatic diseases

Objective. To assess neurohumoral relationship state in pts with systemic vasculitis (SV) and systemic connective tissue diseases. Material and Methods. 54 pts with rheumatic diseases (RS) were included: 18 with systemic lupus erythematosus (SLE), 16 with systemic sclerosis, 20 with systemic vasculitis (SV). Mean age was 49,3 5,4 years. Disease duration varied from 5 to 10 years. Control group consisted of 20 healthy persons. 24- hours ECG monitoring, heart rate variability (HRV) spectral analysis, functional (clinoorthostatic sign) and exercise ECG testing (isometric exercise, dynamic load, veloergometry) were performed. Plasma histamine level, histaminase activity, plasma serotonin, tryptophan-5-hydrolase, oxytriptophandecar- boxylase, MAO levels were examined to assess vasoactive amine system state. Vasoactive amine system slate was assessed on histamine/serotonin ratio. Histamine/histaminase, serotonin/MAO, histaminase/MAO ratios were used to judge inhibitory activity. Results. Compared with control pts with RS showed marked and significant decrease of ergotropic mediators (noradrenaline, adrenaline) and their metabolites concentration which correlated with HRV. Increase of histaminase that processes appropriate biogenic amine excess quantity was found in all forms of RS. More intensive than in healthy persons monoamine metabolism accompanied by their degradation acceleration resulted in enhanced MAO activity (significant in polyarteritis). LF/HF index reflecting summated activity of autonomic influences on heart rate showed significant prevalence of sympathetic effect in SV (3,46 0,31, p&lt;0,05), CRV analysis showed adequate autonomic supply only in 11,7% of pts with RS. Conclusion. Exercise testing in dynamic analysis of quantitative HRV indices should be performed to determine autonomic reactivity ю assess homeostatic possibilities and adaptation reserve in pts with RS

CARDIOVASCULAR EVENTS IN SYSTEMIC LUPUS ERYTHEMATOSUS: MECHANISMS FOR THE ACCELERATED DEVELOPMENT OF ATHEROSCLEROSIS, DIAGNOSIS, CORRECTION CAPABILITIES

Atherosclerosis and its complications are the major cause of late mortality among patients with systemic lupus erythematosus (SLE). SLE and coronary heart disease share common pathophysiological mechanisms associated with systemic and chronic inflammation. At the same time, traditional risk factors, such as hypertension, elderly age, smoking, hypercholesterolemia, obesity, and male sex, cannot fully explain the mechanism for the accelerated development of atherosclerosis in patients with SLE. Specific risk factors, such as its duration, glucocorticoid use, anti-doublestranded (native) DNA autoantibodies and antiphospholipid antibodies, create conditions for the accelerated development of atherosclerosis in this group of patients.The available facts indicate that a rheumatologist can reduce the risk of cardiovascular disease (CVD), by controlling the activity of SLE. Traditional CVD risk factors should be also modified with smoking cessation, weight loss, and blood pressure control. It is necessary to keep in mind the role of anti-inflammatory therapy, in particular the positive effect of drugs, such as anti-malarial drugs and mycophenolate mofetil, and the adverse prognostic effect of prolonged glucocorticoid use. Further studies should assist in elaborating effective risk scales and specific therapeutic programs for the prevention and treatment of CVD in patients with SLE

Blood coagulation parameters and activity indices in patients with systemic lupus erythematosus

Objective. To assess coagulation parameters and activity indices in pts with systemic lupus erythematosus (SLE). Material and methods . 86 pts with SLE (83 female and 3 male) were examined. 12 of them had antiphospholipid syndrome. Mean age was 35,9±1,5 years (from 18 to 58 years), mean disease duration was 9,8+1,4 years. Control group consisted of 60 healthy volunteers with mean age 37,1+4,1 years. SLE activity assessment was performed with SLAM, SLEDAI and ECLAM indices. Results. SLE pts showed 5-fold (p&lt;0,01) increase of spontaneous platelets aggregation and more than 3-fold increase of factor von Willebrand antigen (FWA) concentration. Platelet activation in pts was accompanied by decrease of platelet aggregation with collagen (on 27%), p&lt;0,01. Characteristic sign of coagulation hemostasis activation was significant increase of soluble fibrin-monomer complexes (SFMC) concentration on 81 % (p&lt;0,01) so as increase D-dimers level in 53,3% of pts. Fibrinogen concentration was increased on 29%, spontaneous fibrinolysis parameters were decreased on 20%, antithrombin (AT) 111 - on 21% in comparison with control. Direct correlation between activity indiccs and SFMC(ECLAM, r=0,5), fibrinogen concentration (SLAM, r=0,34), D- dimers level (ECLAM, r=0,5), spontaneous platelet aggregation (ECLAM, r=0,5) so as inverse correlation with AT III activity (SLEDAI, r-0,73) was revealed. Conclusion. Changes of hemostasis parameters in SLE may serve as predictors of thrombotic disorders development and indication to drug correction of blood coagulation disorders. Direct correlation between blood coagulation system activity and indices of SLE activity