scholarly journals Lidar/radar approach to quantify the dust impact on ice nucleation in mid and high level clouds

2019 ◽  
Vol 99 ◽  
pp. 04003
Author(s):  
Albert Ansmann ◽  
Rodanthi-Elisavet Mamouri ◽  
Johannes Bühl ◽  
Patric Seifert ◽  
Ronny Engelmann ◽  
...  
Keyword(s):  
Particle Concentration ◽  
Eastern Mediterranean ◽  
Ice Nucleation ◽  
Saharan Dust ◽  
Ice Crystal ◽  
Cloud Radar ◽  
Field Campaigns ◽  
High Level ◽  
The Relationship

We present the first attempt of a closure experiment regarding the relationship between ice nucleating particle concentration (INPC) and ice crystal number concentration (ICNC), solely based on active remote sensing. The approach combines aerosol and cloud observations with polarization lidar, Doppler lidar, and cloud radar. Several field campaigns were conducted on the island of Cyprus in the Eastern Mediterranean from 2015-2018 to study heterogeneous ice formation in altocumulus and cirrus layers embedded in Saharan dust. A case study observed on 10 April 2017 is discussed in this contribution.

scholarly journals Ice-nucleating particle versus ice crystal number concentrationin altocumulus and cirrus layers embedded in Saharan dust:a closure study

2019 ◽  
Vol 19 (23) ◽  
pp. 15087-15115 ◽  
Author(s):  
Albert Ansmann ◽  
Rodanthi-Elisavet Mamouri ◽  
Johannes Bühl ◽  
Patric Seifert ◽  
Ronny Engelmann ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Convective Cloud ◽  
Terminal Velocity ◽  
Ice Nucleation ◽  
Saharan Dust ◽  
Ice Crystal ◽  
Subsequent Transformation ◽  
Aerosol Cloud ◽  
Parameterization Schemes ◽  
Heterogeneous Ice Nucleation

Abstract. For the first time, a closure study of the relationship between the ice-nucleating particle concentration (INP; INPC) and ice crystal number concentration (ICNC) in altocumulus and cirrus layers, solely based on ground-based active remote sensing, is presented. Such aerosol–cloud closure experiments are required (a) to better understand aerosol–cloud interaction in the case of mixed-phase clouds, (b) to explore to what extent heterogeneous ice nucleation can contribute to cirrus formation, which is usually controlled by homogeneous freezing, and (c) to check the usefulness of available INPC parameterization schemes, applied to lidar profiles of aerosol optical and microphysical properties up to the tropopause level. The INPC–ICNC closure studies were conducted in Cyprus (Limassol and Nicosia) during a 6-week field campaign in March–April 2015 and during the 17-month CyCARE (Cyprus Clouds Aerosol and Rain Experiment) campaign. The focus was on altocumulus and cirrus layers which developed in pronounced Saharan dust layers at heights from 5 to 11 km. As a highlight, a long-lasting cirrus event was studied which was linked to the development of a very strong dust-infused baroclinic storm (DIBS) over Algeria. The DIBS was associated with strong convective cloud development and lifted large amounts of Saharan dust into the upper troposphere, where the dust influenced the evolution of an unusually large anvil cirrus shield and the subsequent transformation into an cirrus uncinus cloud system extending from the eastern Mediterranean to central Asia, and thus over more than 3500 km. Cloud top temperatures of the three discussed closure study cases ranged from −20 to −57 ∘C. The INPC was estimated from polarization/Raman lidar observations in combination with published INPC parameterization schemes, whereas the ICNC was retrieved from combined Doppler lidar, aerosol lidar, and cloud radar observations of the terminal velocity of falling ice crystals, radar reflectivity, and lidar backscatter in combination with the modeling of backscattering at the 532 and 8.5 mm wavelengths. A good-to-acceptable agreement between INPC (observed before and after the occurrence of the cloud layer under investigation) and ICNC values was found in the discussed three proof-of-concept closure experiments. In these case studies, INPC and ICNC values matched within an order of magnitude (i.e., within the uncertainty ranges of the INPC and ICNC estimates), and they ranged from 0.1 to 10 L−1 in the altocumulus layers and 1 to 50 L−1 in the cirrus layers observed between 8 and 11 km height. The successful closure experiments corroborate the important role of heterogeneous ice nucleation in atmospheric ice formation processes when mineral dust is present. The observed long-lasting cirrus event could be fully explained by the presence of dust, i.e., without the need for homogeneous ice nucleation processes.

scholarly journals Ice nucleating particles over the Eastern Mediterranean measured by unmanned aircraft systems

2017 ◽  
Vol 17 (7) ◽  
pp. 4817-4835 ◽  
Author(s):  
Jann Schrod ◽  
Daniel Weber ◽  
Jaqueline Drücke ◽  
Christos Keleshis ◽  
Michael Pikridas ◽  
...  
Keyword(s):  
Transport Model ◽  
Eastern Mediterranean ◽  
Lower Troposphere ◽  
Ground Level ◽  
Ice Nucleation ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Saharan Dust ◽  
Cloud Formation ◽  
Aircraft Systems

Abstract. During an intensive field campaign on aerosol, clouds, and ice nucleation in the Eastern Mediterranean in April 2016, we measured the abundance of ice nucleating particles (INPs) in the lower troposphere from unmanned aircraft systems (UASs). Aerosol samples were collected by miniaturized electrostatic precipitators onboard the UASs at altitudes up to 2.5 km. The number of INPs in these samples, which are active in the deposition and condensation modes at temperatures from −20 to −30 °C, were analyzed immediately after collection on site using the ice nucleus counter FRIDGE (FRankfurt Ice nucleation Deposition freezinG Experiment). During the 1-month campaign, we encountered a series of Saharan dust plumes that traveled at several kilometers' altitude. Here we present INP data from 42 individual flights, together with aerosol number concentrations, observations of lidar backscattering, dust concentrations derived by the dust transport model DREAM (Dust Regional Atmospheric Model), and results from scanning electron microscopy. The effect of the dust plumes is reflected by the coincidence of INPs with the particulate matter (PM), the lidar signal, and the predicted dust mass of the model. This suggests that mineral dust or a constituent related to dust was a major contributor to the ice nucleating properties of the aerosol. Peak concentrations of above 100 INPs std L−1 were measured at −30 °C. The INP concentration in elevated plumes was on average a factor of 10 higher than at ground level. Since desert dust is transported for long distances over wide areas of the globe predominantly at several kilometers' altitude, we conclude that INP measurements at ground level may be of limited significance for the situation at the level of cloud formation.

scholarly journals Gender and feminist considerations in Artificial Intelligence from a developing-world perspective, with India as a case study

2021 ◽  
Author(s):  
SANGHAMITRA CHOUDHURY ◽  
Shailendra Kumar
Keyword(s):  
Artificial Intelligence ◽  
Developing Countries ◽  
Developing World ◽  
Developed Countries ◽  
High Level ◽  
The Impact ◽  
The Relationship ◽  
Precarious Situation ◽  
And Robotics

<p>The relationship between women, technology manifestation, and likely prospects in the developing world is discussed in this manuscript. Using India as a case study, the paper goes on to discuss how ontology and epistemology views utilised in AI (Artificial Intelligence) and robotics will affect women's prospects in developing countries. Women in developing countries, notably in South Asia, are perceived as doing domestic work and are underrepresented in high-level professions. They are disproportionately underemployed and face prejudice in the workplace. The purpose of this study is to determine if the introduction of AI would exacerbate the already precarious situation of women in the developing world or if it would serve as a liberating force. While studies on the impact of AI on women have been undertaken in developed countries, there has been less research in developing countries. This manuscript attempts to fill that need.</p>

Evaluation of congress performance and congress attendees' satisfaction - a case study of Novi Sad (Serbia)

2011 ◽  
Vol 17 (1) ◽  
pp. 67-78
Author(s):  
Vanja Dragićević ◽  
Uglješa Stankov ◽  
Tanja Armenski ◽  
Snežana Štetić
Keyword(s):  
Destination Choice ◽  
International Meeting ◽  
International Industry ◽  
High Level ◽  
Novi Sad ◽  
Destination Management Organizations ◽  
Intention To Return ◽  
The Relationship ◽  
The City

The congress industry is a young, dynamic industry, which is growing and maturing at a rapid rate. It is now a truly international industry, witnessing huge investments across all continents. Due to economic and other benefits of a more intangible nature, the number of congress destinations and venues worldwide is growing. In order to provide the sustainability of congress destinations and venues, it is important to examine congress delegates’ experience, their overall satisfaction as well as behavioural intentions regarding destination. This study was conducted in the city of Novi Sad, which is after Belgrade the most important international meeting destination in Serbia. The purpose of this study is to examine the experience and overall satisfaction of the attendees at international congresses held in Novi Sad. Also, the relationship between overall satisfaction, word-of-mouth and intention to return were examined. A questionnaire survey was used as an instrument for the study. The collected data were analyzed using SPSS standard package. The results showed high level of attendees’ satisfaction with the congress elements and with destination choice. Also, the results confirmed that Novi Sad has a great potential for development of congress tourism, as the majority of the respondents show great interest to visit Novi Sad again and they would recommend city as a meeting destination. The results of this study are valuable for congress centre managers and for destination management organizations.

How to Use Information Technology Effectively to Achieve Business Objectives

2012 ◽  
pp. 19-35
Author(s):  
Antonio Goncalves ◽  
Natália Serra ◽  
José Serra ◽  
Pedro Sousa
Keyword(s):  
Information Technology ◽  
Software Development ◽  
Enterprise Architecture ◽  
Planning Strategy ◽  
The Business Cycle ◽  
High Level ◽  
Architecture Development ◽  
The Relationship ◽  
Dynamic Alignment

In this chapter the authors show, by using a case study, how it is possible to achieve the alignment between business and Information Technology (IT). It describes several phases of project development, from planning strategy, enterprise architecture, development of businesses supporting tools and keeping dynamic alignment between the business and the IT. The authors propose a framework, framed under an enterprise architecture that guarantees a high level of response to the applications development or configuration as improves its alignment to business by solving some limitations of traditional software development solutions namely: difficulty in gathering clients requirements, which should be supported by the applications; difficulty to connect the organisation processes used to answer the client, which must also be integrated in the applications and the difficulty to develop the applications that can follow the business cycle. To test the approach, this was applied to a real case study consisting in the configuration of an application that manages the relationship with the clients.

China's Streets Lighting Environment Impact Factors Analysis

2013 ◽  
Vol 409-410 ◽  
pp. 1036-1039
Author(s):  
Xiao Ming Su ◽  
Ming Yu Zhang ◽  
Zhan Guo Hao
Keyword(s):  
Surface Brightness ◽  
Impact Factors ◽  
Environment Impact ◽  
Street Lighting ◽  
Surface Conditions ◽  
Factors Analysis ◽  
Lighting Environment ◽  
High Level ◽  
The Relationship

This paper proposed a new method of describing street glare. Glare is a typical light environment, it is affected by streetlights and street surface conditions. It impact on street safety. This paper based on survey of Tianjin, Changsha, Zhengzhou street area, included optical lights types, height of light bulbs, distance between tow lights, street surface brightness, illumination and other factors examination and record. Survey date had been used to set 36 street lighting simulated models and compare with the calculation. The output for the analysis is a series of maps reflecting the relationship between street glare environment and its factors. The case study proved that street lighting environment is closely associated with streetlights bulbs brightness and its installation site. The results show that high level of light brightness will lead to high level of glare and higher light bulbs will increase glare.

scholarly journals Aerosol specification in single-column CAM5

2014 ◽  
Vol 7 (6) ◽  
pp. 7693-7731
Author(s):  
B. Lebassi-Habtezion ◽  
P. Caldwell
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Strong Dependence ◽  
Ice Nucleation ◽  
Ice Crystal ◽  
Shallow Convection ◽  
Single Column ◽  
The Impact

Abstract. The ability to run a global climate model in single-column mode is very useful for testing model improvements because single-column models (SCMs) are inexpensive to run and easy to interpret. A major breakthrough in Version 5 of the Community Atmosphere Model (CAM5) is the inclusion of prognostic aerosol. Unfortunately, this improvement was not coordinated with the SCM version of CAM5 and as a result CAM5-SCM initializes aerosols to zero. In this study we explore the impact of running CAM5-SCM with aerosol initialized to zero (hereafter named Default) and test three potential fixes. The first fix is to use CAM5's prescribed aerosol capability, which specifies aerosols at monthly climatological values. The second method is to prescribe aerosols at observed values. The third approach is to fix droplet and ice crystal numbers at prescribed values. We test our fixes in four different cloud regimes to ensure representativeness: subtropical drizzling stratocumulus (based on the DYCOMS RF02 case study), mixed-phase Arctic stratocumulus (using the MPACE-B case study), tropical shallow convection (using the RICO case study), and summertime mid-latitude continental convection (using the ARM95 case study). Stratiform cloud cases (DYCOMS RF02 and MPACE-B) were found to have a strong dependence on aerosol concentration, while convective cases (RICO and ARM95) were relatively insensitive to aerosol specification. This is perhaps expected because convective schemes in CAM5 do not currently use aerosol information. Adequate liquid water content in the MPACE-B case was only maintained when ice crystal number concentration was specified because the Meyers et al. (1992) deposition/condensation ice nucleation scheme used by CAM5 greatly overpredicts ice nucleation rates, causing clouds to rapidly glaciate. Surprisingly, predicted droplet concentrations for the ARM95 region in both SCM and global runs were around 25 cm−3, which is much lower than observed. This finding suggests that CAM5 has problems capturing aerosol effects in this climate regime.

scholarly journals A Bayesian Best-Worst Method-Based Multicriteria Competence Analysis of Crowdsourcing Delivery Personnel

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Longxiao Li ◽  
Xu Wang ◽  
Jafar Rezaei
Keyword(s):  
Customer Service ◽  
Value Function ◽  
Service Network ◽  
Core Elements ◽  
Delivery Platform ◽  
High Level ◽  
The Relationship ◽  
Best Worst Method

Crowdsourcing delivery is becoming a prevalent tool for tackling delivery problems by building a large labor-intensive service network. In this network, the delivery personnel consist of a large number of people with a complex composition and high level of mobility, creating enormous challenges for the quality of service and the management of a crowdsourcing platform. Hence, we attempt to conduct a competence analysis to determine whether they can provide promised services with high quality, i.e., they are competent for their job. To this end, the competence theory is introduced, and a multicriteria competence analysis (MCCA) approach is developed. To illustrate the MCCA approach, a real-world case study is conducted involving a Chinese takeaway delivery platform, where the Bayesian best-worst method is used to determine the weights of the criteria based on the data collected from managers of the platform company. Also, the competence scores of the personnel involved are collected through surveys and data sources of the company. Given the weights and the competence scores, we use additive value function to identify the overall competence scores of them, which reflects the level of competence for their job. The results show that Skills is the most important competence, while Knowledge is the least important of the four competence dimensions. In subcriteria, four core elements are identified such as punctuality, customer service awareness, responsible, and goods intact. In addition to the importance of criteria, a ranking of a sample of personnel is provided, and almost half of the crowdsourcing delivery personnel’s competence is below the average and vary significantly, while the relationship between the competence level and some other variables is also discussed. Moreover, the developed MCCA approach in this paper can be applied to analyze the competence of personnel in many other industries as well.

Study on the Measurement of Industrial Structure “Sophistication, Rationalization and Ecologicalization” Based on the Dynamic Analysis of Grey Relations — A Case Study of Beijing-Tianjin-Hebei

2020 ◽  
Vol 8 (2) ◽  
pp. 130-147
Author(s):  
Shiyi Yuan ◽  
Xiaopeng Sun ◽  
Weiguo Chen ◽  
Yongwu Li
Keyword(s):  
Economic Growth ◽  
Industrial Structure ◽  
Structure Optimization ◽  
Coordinated Development ◽  
Economic Growth Rate ◽  
Dynamic Correlation ◽  
Industrial Structure Optimization ◽  
High Level ◽  
The Relationship

AbstractThe Beijing-Tianjin-Hebei region is one of the regions with the most dynamic economies, highest degrees of openness, strongest innovation capacities and largest populations, as well as an important engine driving China’s economic development. Currently, the development of the Beijing-Tianjin-Hebei region faces many difficulties, including an inefficient distribution of regional functions, imbalance in industrial structure, low sophistication, and serious overburdening of resources and the environment. Promoting the overall coordinated development of the region has become an urgent challenge. In this paper, according to the conventions of industrial structure optimization, the three core indicators of regional industrial structure rationalization, sophistication and ecologicalization are constructed. With the help of the grey dynamic correlation model, the three indicators are coupled with the economic growth rate, and the industrial structure optimization index of the Beijing-Tianjin-Hebei region is comprehensively measured. The study shows that rationalization of the industrial structure in the Beijing-Tianjin-Hebei region is increasing but that this trend is not obvious; sophistication of the industrial structure is relatively high and has also been operating at a high level; however, the overall ecological level of the industrial structure in the Beijing-Tianjin-Hebei region is not high and presents the characteristics of high in the middle and low at both ends. In terms of the relationship between industrial structure and economic growth in the Beijing-Tianjin-Hebei region, ecologicalization of the industrial structure has the greatest influence on economic growth, followed by sophistication of the industrial structure, and rationalization of the industrial structure has the weakest influence.

scholarly journals Tropical tele-connections to the Mediterranean climate and weather

2005 ◽  
Vol 2 ◽  
pp. 157-160 ◽  
Author(s):  
P. Alpert ◽  
C. Price ◽  
S. O. Krichak ◽  
B. Ziv ◽  
H. Saaroni ◽  
...  
Keyword(s):  
Climate Variability ◽  
Mediterranean Climate ◽  
Indian Monsoon ◽  
Eastern Mediterranean ◽  
Summer Season ◽  
Saharan Dust ◽  
Severe Flood ◽  
Summer Temperatures ◽  
The Relationship ◽  
Tropical Systems

Abstract. Some strong natural fluctuations of climate in the Eastern Mediterranean (EM) region are shown to be connected to the major tropical systems. Potential relations between EM rainfall extremes to tropical systems, e.g. El Niño, Indian Monsoon and hurricanes, are demonstrated. For a specific event, high resolution modelling of the severe flood on 3-5 December 2001 in Israel suggests a relation to hurricane Olga. In order to understand the factors governing the EM climate variability in the summer season, the relationship between extreme summer temperatures and the Indian Monsoon was examined. Other tropical factors like the Red-Sea Trough system and the Saharan dust are also likely to contribute to the EM climate variability.

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