Time distribution of thunderstorms observed at Odesa AMSC at the beginning of the 21st century

The article presents the results of the research of thunderstorm activity at Odesa AMSC for the period of 2000-2019. Under conditions of intense warming, thunderstorm activity responds to the changes of temperature, humidity, radiation regime and atmospheric composition. Modern climate changes that are characterized by rising air temperatures have a decisive influence on the conditions under which dangerous weather phenomena are formed, thus monitoring of the thunderstorms formation in Ukraine is of great importance. The research includes the analysis of synoptic conditions of thunderstorm activity formation such as air-mass processes, frontal activity, and studies daily and daytime variability of the number of thunderstorm cases for the given period. The results of everyday meteorological observations of atmospheric phenomena conducted by Odesa AMSC within the period of 2000-2019 were used as input data to determine the characteristics of thunderstorm activity over city of Odesa. In order to identify the presence, time and duration of thunderstorm activity aviation weather diaries AV-6 were also reviewed. Certain synoptic materials were used to analyze the types of phenomena. Such materials include interactive database ARMsyn, surface synoptic charts for the periods of observation before and during the thunderstorms. It was established that during the period under study air-mass thunderstorms were formed in 370 cases of thunderstorm activity observed at the given observation post. Frontal thunderstorms occur less often: 241 cases over 20 years. The largest number of such thunderstorms is cold front thunderstorms amounting to 129 cases. 75 of them were identified as occlusion front thunderstorms. The least frequent were warm front thunderstorms – only 37 cases constituting 15% of the total number of frontal formations. During the studied period a total number of 620 thunderstorm cases was recorded, 195 of which are dry thunderstorms. Considerable attention is paid to the daily and daytime variability of thunderstorm cases number recorded by Odesa AMSC. With relation to the daily variation, more thunderstorms are observed during daytime amounting to 393 cases, 130 of which are dry thunderstorms. Night thunderstorms amount to 227 cases, 65 of which are dry thunderstorms. With relation to daytime distribution, more thunderstorms were detected in the afternoon.

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Processes contributing to cloud dissipation and formation events on the North Slope of Alaska

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-4149-2021 ◽

2021 ◽

Vol 21 (5) ◽

pp. 4149-4167

Author(s):

Joseph Sedlar ◽

Adele Igel ◽

Hagen Telg

Keyword(s):

Cloud Formation ◽

North Slope ◽

Near Surface ◽

Air Mass ◽

Low Level ◽

Clear Sky ◽

The North ◽

Synoptic Conditions ◽

North Slope Of Alaska ◽

Low Cloud

Abstract. Clear-sky periods across the high latitudes have profound impacts on the surface energy budget and lower atmospheric stratification; however an understanding of the atmospheric processes leading to low-level cloud dissipation and formation events is limited. A method to identify clear periods at Utqiaġvik (formerly Barrow), Alaska, during a 5-year period (2014–2018) is developed. A suite of remote sensing and in situ measurements from the high-latitude observatory are analyzed; we focus on comparing and contrasting atmospheric properties during low-level (below 2 km) cloud dissipation and formation events to understand the processes controlling clear-sky periods. Vertical profiles of lidar backscatter suggest that aerosol presence across the lower atmosphere is relatively invariant during the periods bookending clear conditions, which suggests that a sparsity of aerosol is not frequently a cause for cloud dissipation on the North Slope of Alaska. Further, meteorological analysis indicates two active processes ongoing that appear to support the formation of low clouds after a clear-sky period: namely, horizontal advection, which was dominant in winter and early spring, and quiescent air mass modification, which was dominant in the summer. During summer, the dominant mode of cloud formation is a low cloud or fog layer developing near the surface. This low cloud formation is driven largely by air mass modification under relatively quiescent synoptic conditions. Near-surface aerosol particles concentrations changed by a factor of 2 around summer formation events. Thermodynamic adjustment and increased aerosol presence under quiescent atmospheric conditions are hypothesized as important mechanisms for fog formation.

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A Heat-Balance Study on Sørbreen, Jan Mayen

Journal of Glaciology ◽

10.3189/s0022143000018852 ◽

1965 ◽

Vol 5 (42) ◽

pp. 793-803

Author(s):

P. C. Dibben

Keyword(s):

Heat Transfer ◽

Heat Balance ◽

Summer Rainfall ◽

Weather Conditions ◽

Meteorological Station ◽

Sensible Heat ◽

Balance Study ◽

Statistical Comparison ◽

Air Temperatures ◽

Frontal Activity

AbstractThe techniques and results of a heat-balance programme on Sørbreen, Jan Mayen, are presented and discussed. Estimates of 24 hr. heat-transfer totals under frontal and non-frontal weather conditions are then made. Transfer is found to be higher during frontal conditions, due to an increase in latent and to a lesser extent sensible heat transfer. Consideration of upper air temperatures and humidities suggests this higher transfer is experienced by the glacier as a whole. It is then proposed that summer rainfall totals will provide an index of frontal activity which may be used to indicate relative ablation from one summer to another. A statistical comparison of ablation measured on the glacier and rainfall recorded at the Jan Mayen meteorological station supports this suggestion.

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The Mass of the Atmosphere: A Constraint on Global Analyses

Journal of Climate ◽

10.1175/jcli-3299.1 ◽

2005 ◽

Vol 18 (6) ◽

pp. 864-875 ◽

Cited By ~ 122

Author(s):

Kevin E. Trenberth ◽

Lesley Smith

Keyword(s):

Water Vapor ◽

Surface Pressure ◽

Total Mass ◽

Precipitable Water ◽

Atmospheric Composition ◽

Specific Humidity ◽

Air Mass ◽

Dry Air ◽

Annual Range ◽

Global Mean

Abstract The total mass of the atmosphere varies mainly from changes in water vapor loading; the former is proportional to global mean surface pressure and the water vapor component is computed directly from specific humidity and precipitable water using the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analyses (ERA-40). Their difference, the mass of the dry atmosphere, is estimated to be constant for the equivalent surface pressure to within 0.01 hPa based on changes in atmospheric composition. Global reanalyses satisfy this constraint for monthly means for 1979–2001 with a standard deviation of 0.065 hPa. New estimates of the total mass of the atmosphere and its dry component, and their corresponding surface pressures, are larger than previous estimates owing to new topography of the earth’s surface that is 5.5 m lower for the global mean. Global mean total surface pressure is 985.50 hPa, 0.9 hPa higher than previous best estimates. The total mean mass of the atmosphere is 5.1480 × 1018 kg with an annual range due to water vapor of 1.2 or 1.5 × 1015 kg depending on whether surface pressure or water vapor data are used; this is somewhat smaller than the previous estimate. The mean mass of water vapor is estimated as 1.27 × 1016 kg and the dry air mass as 5.1352 ± 0.0003 × 1018 kg. The water vapor contribution varies with an annual cycle of 0.29-hPa, a maximum in July of 2.62 hPa, and a minimum in December of 2.33 hPa, although the total global surface pressure has a slightly smaller range. During the 1982/83 and 1997/98 El Niño events, water vapor amounts and thus total mass increased by about 0.1 hPa in surface pressure or 0.5 × 1015 kg for several months. Some evidence exists for slight decreases following the Mount Pinatubo eruption in 1991 and also for upward trends associated with increasing global mean temperatures, but uncertainties due to the changing observing system compromise the evidence. The physical constraint of conservation of dry air mass is violated in the reanalyses with increasing magnitude prior to the assimilation of satellite data in both ERA-40 and the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalyses. The problem areas are shown to occur especially over the Southern Oceans. Substantial spurious changes are also found in surface pressures due to water vapor, especially in the Tropics and subtropics prior to 1979.

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Connected Variations of Meteorological and Electrical Quantities of Surface Atmosphere under the Influence of Heavy Rain

Atmosphere ◽

10.3390/atmos11111195 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1195

Author(s):

Vladimir Kalchikhin ◽

Alexey Kobzev ◽

Petr Nagorskiy ◽

Mariya Oglezneva ◽

Konstantin Pustovalov ◽

...

Keyword(s):

Electrical Conductivity ◽

Surface Layer ◽

Heavy Rainfall ◽

Atmospheric Precipitation ◽

Heavy Rain ◽

Air Masses ◽

Surface Atmosphere ◽

Synoptic Conditions ◽

Electrical State ◽

Atmospheric Phenomena

The electrical state of the surface atmosphere changes significantly under the influence of cloudiness and atmospheric phenomena, including atmospheric precipitation. These features can be used for possible diagnostics of precipitation and improvement of their characteristics based on variations of atmospheric-electrical quantities in the surface layer. Studies of variations of meteorological and atmospheric-electrical quantities in the surface layer were carried out during the heavy rainfall associated with the cumulonimbus (Cb) clouds passage. Meteorological and atmospheric-electrical observations in the Geophysical Observatory of the Institute of Monitoring of Climatic and Ecological Systems are presented in this paper. Precipitation data are used to identify periods of heavy rainfall ≥ 5 mm/h. Information of weather stations and satellites is used to separate the heavy rainfall events by synoptic conditions like thunderstorms and showers of frontal or internal air masses. We find that rains associated with the frontal Cb clouds produce more abrupt changes in negative electrical conductivity in comparison with the Cb clouds in internal air masses. The significant increase in negative electrical conductivity (more than two times vs. normal values) occurs typically during the passage of frontal Cb and heavy rain with droplet size greater than 4 mm.

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Proxy-based 300-year High Arctic climate warming record from Svalbard

Polar Record ◽

10.1017/s0032247419000275 ◽

2019 ◽

Vol 55 (3) ◽

pp. 132-141 ◽

Cited By ~ 1

Author(s):

Tomi P. Luoto ◽

Antti E. K. Ojala ◽

Marek Zajaczkowski

Keyword(s):

Climate Warming ◽

Break Point ◽

Warming Trend ◽

High Arctic ◽

Ice Age ◽

Arctic Climate ◽

Air Temperatures ◽

Summer Temperatures ◽

Meteorological Observations ◽

Arctic Climate Change

AbstractWe used fossil Chironomidae assemblages and the transfer function approach to reconstruct summer air temperatures over the past 300 years from a High Arctic lake in Hornsund, Svalbard. Our aims were to compare reconstructed summer temperatures with observed (last 100 years) seasonal temperatures, to determine a potential climate warming break point in the temperature series and to assess the significance and rate of the climate warming trend at the study site. The reconstructed temperatures were consistent with a previous proxy record from Svalbard and showed good correlation with the meteorological observations from Bjørnøya and Longyearbyen. From the current palaeoclimate record, we found a significant climate warming threshold in the 1930s, after which the temperatures rapidly increased. We also found that the climate warming trend was strong and statistically significant. Compared with the reconstructed Little Ice Age temperatures in late eighteenth century cooling culmination, the present day summer temperatures are >4°C higher and the temperature increase since the 1930s has been 0.5°C per decade. These results highlight the exceptionally rapid recent warming of southern Svalbard and add invaluable information on the seasonality of High Arctic climate change and Arctic amplification.

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Atmospheric satellite-based and in situ surface observations on summertime trace gases (CO, CO2, CH4) over the metropolitan area of Bucharest

10.5194/egusphere-egu2020-4930 ◽

2020 ◽

Author(s):

Marius-Paul Corbu ◽

Andreea Calcan ◽

Ioana Vizireanu ◽

Denisa Elena Moaca ◽

Robert-Valentin Chiritescu ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Metropolitan Area ◽

Financial Support ◽

Trace Gases ◽

Air Pollutant ◽

Data Set ◽

Air Mass ◽

Synoptic Conditions

Although anthropogenic emissions of trace gases have decreased over the last decades in Europe, strong additional reductions are required to reach the goals of the Paris climate agreements. In addition, air pollution is an issue of great concern for the inhabitants of the metropolitan area of Bucharest, as the local air quality is often poor. The rapid development of the city, increased traffic volume from a mixed vehicle fleet (different technologies and fuels), and other factors are strong contributors of emissions of greenhouse gases and air pollutants in Bucharest.The goal of this research was the assessment of CO, CO2 and CH4 concentrations in Bucharest, identification of potential emissions hotspots and their causes (anthropogenic or natural/biogenic, local or distant) and determination of the background values.Measurements were performed in summer 2019 in four districts of Bucharest covering about two thirds of the metropolitan area during the Romanian Methane Emissions from Oil&gas (ROMEO) campaign with high resolution (1 sec). These data sets were complemented with satellite observations of CO and CH4 from Copernicus Sentinel-5P at a resolution of 7 km2.Hourly meteorological data, temperature, relative humidity, wind speed and direction, and atmospheric pressure were added to the air pollutant data set because synoptic conditions can strongly influence the levels of pollution. Air mass origins were investigated by computing backward air mass trajectories using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model for 72 hours back.Points of high concentrations of CO, CO2, CH4 near the surface were identified which are, most likely, linked to local anthropogenic activities in the nearby surroundings. We identified a variation of concentrations of CO from 0.01 to 101 ppm, of CO2 from 388 to 6556 ppm, and of CH4 from 1.89 to 246 ppm, while background levels are as follows: 0.071&#177;0.042 ppm CO, 392.68&#177;3.01 ppm CO2, and 1.93&#177;0.016 ppm CH4.Results of our study provide an up to date quantitative image of CO, CO2, CH4 hotspots in the Bucharest area, which is important for modeling air quality and may also help to improve the relationships between column integrated air pollution data with in situ ground observations.Acknowledgement:This research is supported by ROMEO project, developed under UNEP&#8217;s financial support PCA/CCAC/UU/DTIE19-EN652. Partial financial support from UB198/Int project is also acknowledged.The authors acknowledge the free use of tropospheric CO and CH4 column data from TROPOMI (Sentinel-5P) sensor from https://s5phub.copernicus.eu and the NOAA Air Resources Laboratory for the provision of the HYSPLIT transport model available at READY website https://www.ready.noaa.govSpecial thanks to all INCAS technical staff for their support in performing the campaigns.

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Synoptic control on snow avalanche activity in central Spitsbergen

10.5194/tc-2021-48 ◽

2021 ◽

Author(s):

Holt Hancock ◽

Jordy Hendrikx ◽

Markus Eckerstorfer ◽

Siiri Wickström

Keyword(s):

Environmental Change ◽

Atmospheric Circulation ◽

High Arctic ◽

Snow Avalanche ◽

Atmospheric Conditions ◽

Svalbard Archipelago ◽

Atmospheric Circulation Patterns ◽

Wind Speeds ◽

Air Temperatures ◽

Synoptic Conditions

Abstract. Atmospheric circulation exerts an important control on a region's snow avalanche activity by broadly determining the mountain weather patterns which influence snowpack development and avalanche release. In central Spitsbergen, the largest island in the high-Arctic Svalbard archipelago, avalanches are a common natural hazard throughout the winter months. Previous work has identified a unique snow climate reflecting the region's climatically dynamic environmental setting but has not specifically addressed the synoptic-scale control of atmospheric circulation on avalanche activity here. In this work, we investigate atmospheric circulation's control on snow avalanching in the Nordenskiöld Land region of central Spitsbergen by first constructing a four-season (2016/2017–2019/2020) regional avalanche activity record using observations available on a database used by the Norwegian Water Resources and Energy Directorate (NVE). We then analyze the synoptic atmospheric conditions on days with differing avalanche activity situations. Our results show synoptic conditions conducive to elevated precipitation, wind speeds, and air temperatures near Svalbard are associated with increased avalanche activity in Nordenskiöld Land, but different synoptic signals exist for days characterized by dry, mixed, and wet avalanche activity. Differing upwind conditions help further explain differences in the frequency and nature of avalanche activity resulting from these various atmospheric circulation patterns. We further employ a daily atmospheric circulation calendar to help contextualize our results in the growing body of literature related to environmental change in this location. This work helps expand our understanding of snow avalanches in Svalbard to a broader spatial scale and provides a basis for future work investigating the impacts of environmental change on avalanche activity in Svalbard and other locations where avalanche regimes are impacted by changing climatic and synoptic conditions.

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The meteorological observations made by Alexander Zawadzki in Brno, 1861–1867

Geografie ◽

10.37040/geografie2013118040334 ◽

2013 ◽

Vol 118 (4) ◽

pp. 334-355 ◽

Cited By ~ 1

Author(s):

Rudolf Brázdil ◽

Ladislava Řezníčková ◽

Hubert Valášek

Keyword(s):

Secondary School ◽

Air Temperature ◽

Wind Direction ◽

Great Distance ◽

Air Pressure ◽

Phenological Data ◽

Meteorological Observations ◽

Czech Lands ◽

Technical Secondary School ◽

Atmospheric Phenomena

The observations made by Pavel Olexík in 1848 are accepted as the beginning of standardised meteorological measurements in Brno. Three times every day, from September 1861 to December 1867, Professor Alexander Zawadzki, a teacher of physics and botany at a Brno technical secondary school, kept recording the values of air pressure, air temperature, precipitation, wind and atmospheric phenomena. His observation diary also includes phenological data and information about meteorological and other natural events across the Czech Lands and Europe. Because there is neither a great distance nor difference in altitude between the places in which Zawadzki and Olexík made their observations, the pressure and temperature readings show only negligible divergences. The differences are not significant for wind direction, precipitation totals and days with rain and snow, but they are greater for atmospheric phenomena. The contemporary meteorological activities of Gregor Johann Mendel also vastly contributed to Brno becoming an important centre of meteorology in the eastern part of the Czech Lands in the 1860s.

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Potential and Use of Solar Energy in Primorye Region (Russia)

Solar Energy ◽

10.1115/isec2004-65058 ◽

2004 ◽

Author(s):

Oleg P. Kovalev ◽

Alexandr V. Volkov

Keyword(s):

Solar Radiation ◽

Solar Energy ◽

Hot Water ◽

Solar Collectors ◽

Heating Systems ◽

Primorye Region ◽

Solar Radiation Flux ◽

Radiation Regime ◽

The Given

During long-term time, the laboratory of non-traditional energetic is been busy with development and introduction of solar water heating systems for hot water supply. The systems with solar collectors of 40 m2 area have been developed and introducted. For estimation of their efficiency we should know flux density of solar radiation, proceeding to surface at the given place. However in Primorye Region at actinometrical watching only four meteostations in the Southern part are carrying out straight measurements of solar radiation flux, and the others record data which concern only solar radiation regime (the amount of solar radiation hours, relation of watching duration of solar radiation to possible duration, the amount of days without sun, etc.). We suggested the expression, which according to know data of solar radiation and cloudiness, recorded practically on all meteorological stations gives possibility to calculate for Primorye Region month sums of total radiation proceeding to horizontal surface. The comparison of estimated values with measured ones gives the error to 3...9% with regard to average many years values, and are in the range of variability of measured values for separate years. In Primorye Region more than 250 m2 of solar collectors were installed; and among them 150 m2 were developed with the laboratory, to position on 2003.11.01. NOTE: This paper was presented at the 2004 International Solar Energy Conference and was inadvertently omitted from the 2004 ASME proceedings. The page range refers to the 2005 International Solar Energy Conference Print Proceedings, where it was subsequently published.

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Observational Evidence of Neighborhood Scale Reductions in Air Temperature Associated with Increases in Roof Albedo

Climate ◽

10.3390/cli6040098 ◽

2018 ◽

Vol 6 (4) ◽

pp. 98 ◽

Cited By ~ 6

Author(s):

Arash Mohegh ◽

Ronnen Levinson ◽

Haider Taha ◽

Haley Gilbert ◽

Jiachen Zhang ◽

...

Keyword(s):

Los Angeles ◽

Air Temperature ◽

Robust Regression ◽

Spatial Density ◽

Daily Average ◽

Air Temperatures ◽

San Fernando ◽

Weather Stations ◽

Meteorological Observations ◽

Neighborhood Scale

The effects of neighborhood-scale land use and land cover (LULC) properties on observed air temperatures are investigated in two regions within Los Angeles County: Central Los Angeles and the San Fernando Valley (SFV). LULC properties of particular interest in this study are albedo and tree fraction. High spatial density meteorological observations are obtained from 76 personal weather-stations. Observed air temperatures were then related to the spatial mean of each LULC parameter within a 500 m radius “neighborhood” of each weather station, using robust regression for each hour of July 2015. For the neighborhoods under investigation, increases in roof albedo are associated with decreases in air temperature, with the strongest sensitivities occurring in the afternoon. Air temperatures at 14:00–15:00 local daylight time are reduced by 0.31 °C and 0.49 °C per 1 MW increase in daily average solar power reflected from roofs per neighborhood in SFV and Central Los Angeles, respectively. Per 0.10 increase in neighborhood average albedo, daily average air temperatures were reduced by 0.25 °C and 1.84 °C. While roof albedo effects on air temperature seem to exceed tree fraction effects during the day in these two regions, increases in tree fraction are associated with reduced air temperatures at night.

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