scholarly journals Evaluation of the MOZAIC Capacitive Hygrometer during the airborne field study CIRRUS-III

2014 ◽  
Vol 7 (9) ◽  
pp. 9803-9838 ◽  
Author(s):  
P. Neis ◽  
H. G. J. Smit ◽  
M. Krämer ◽  
N. Spelten ◽  
A. Petzold
Keyword(s):  
Field Study ◽  
Laser System ◽  
Distribution Functions ◽  
Tunable Diode Laser ◽  
Data Set ◽  
Ice Clouds ◽  
Clear Sky ◽  
Closed Cell ◽  
Passenger Aircraft ◽  
Good Agreement

Abstract. The MOZAIC Capacitive Hygrometer (MCH) is usually operated onboard of passenger aircraft in the framework of MOZAIC (Measurement of Ozone by AIRBUS In-Service Aircraft). In order to evaluate the performance of the MCH, it was operated aboard a Learjet 35A aircraft as part of the CIRRUS-III field study together with a closed-cell Lyman-α fluorescence hygrometer (FISH) and an open path tunable diode laser system (OJSTER) for water vapour measurement. After reducing the data set to MOZAIC-relevant conditions, the 1Hz relative humidity (RH) cross correlation between MCH and reference instruments FISH (clear sky) and OJSTER (in-cirrus) yielded a remarkably good agreement of R2 = 0.97 and slope m = 0.96 and provided the MCH uncertainty of 5% RH. Probability distribution functions of RH deduced from MCH and reference instruments agreed well over the entire range of observations. The main limitation for the use of MCH data is related to sensor temperatures below the calibration limit of Tsensor = −40 °C (corresponds to ambient temperature of Tambient = −70 °C at typical cruising speed of long-haul passenger aircraft), which causes a delay in the sensor's time response. Good performance of MCH for clear sky as well as for in-cirrus conditions demonstrated the sensor robustness also for operation inside ice clouds.

scholarly journals Evaluation of the MOZAIC Capacitive Hygrometer during the airborne field study CIRRUS-III

2015 ◽  
Vol 8 (3) ◽  
pp. 1233-1243 ◽  
Author(s):  
P. Neis ◽  
H. G. J. Smit ◽  
M. Krämer ◽  
N. Spelten ◽  
A. Petzold
Keyword(s):  
Ambient Temperature ◽  
Field Study ◽  
Laser System ◽  
Distribution Functions ◽  
Tunable Diode Laser ◽  
Data Set ◽  
Clear Sky ◽  
Operation Conditions ◽  
Open Path ◽  
Passenger Aircraft

Abstract. The MOZAIC Capacitive Hygrometer (MCH) is usually operated aboard passenger aircraft in the framework of MOZAIC (Measurement of Ozone by Airbus In-Service Aircraft) for measuring atmospheric relative humidity (RH). In order to evaluate the performance of the MCH, the instrument was operated aboard a Learjet 35A research aircraft as part of the CIRRUS-III field study together with a closed-cell Lyman-α fluorescence hygrometer (Fast in situ Stratospheric Hygrometer, or FISH) and an open-path tunable diode laser system (Open-path Jülich Stratospheric TDL ExpeRiment, or OJSTER) for water vapour measurement. After reducing the CIRRUS-III data set to data corresponding to MOZAIC aircraft operation conditions, the 1 Hz RH data cross correlation between the MCH and reference instruments FISH (clear sky) and OJSTER (in-cirrus) yielded a remarkably good agreement of R2 = 0.92 and slope m = 1.02 and provided a MCH uncertainty of 5% RH. Probability distribution functions of RH deduced from the MCH and reference instruments agreed well between 10 and 70% RH with respect to liquid water in the ambient temperature range of ca. −70 to −40 °C. The use of MCH data is limited to sensor temperatures above the calibration limit of Tsensor = −40 °C (corresponds to ambient temperature of Tambient = −70 °C at typical cruising speed of long-haul passenger aircraft). Good performance of the MCH for clear sky as well as for in-cirrus conditions demonstrated the sensor robustness also for operation inside ice clouds.

scholarly journals Statistical analysis of water vapour and ozone in the UT/LS observed during SPURT and MOZAIC

2008 ◽  
Vol 8 (22) ◽  
pp. 6603-6615 ◽  
Author(s):  
A. Kunz ◽  
C. Schiller ◽  
F. Rohrer ◽  
H. G. J. Smit ◽  
P. Nedelec ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Water Vapour ◽  
Trace Gases ◽  
Distribution Functions ◽  
Variance Analysis ◽  
Trace Gas ◽  
Data Sets ◽  
Data Set ◽  
Atmospheric Processes ◽  
Passenger Aircraft

Abstract. A statistical analysis for the comparability of water (H2O) and ozone (O3) data sets sampled during the SPURT aircraft campaigns and the MOZAIC passenger aircraft flights is presented. The Kolmogoroff-Smirnoff test reveals that the distribution functions from SPURT and MOZAIC trace gases differ from each other with a confidence of 95%. A variance analysis shows a different variability character in both trace gas data sets. While the SPURT H2O data only contain atmospheric processes variable on a diurnal or synoptical timescale, MOZAIC H2O data also reveal processes, which vary on inter-seasonal and seasonal timescales. The SPURT H2O data set does not represent the full MOZAIC H2O variance in the UT/LS for climatological investigations, whereas the variance of O3 is much better represented. SPURT H2O data are better suited in the stratosphere, where the MOZAIC RH sensor looses its sensitivity.

scholarly journals Technical Note: Reanalysis of upper troposphere humidity data from the MOZAIC programme for the period 1994 to 2009

2014 ◽  
Vol 14 (13) ◽  
pp. 18905-18942 ◽  
Author(s):  
H. G. J. Smit ◽  
S. Rohs ◽  
P. Neis ◽  
D. Boulanger ◽  
M. Krämer ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Calibration Procedure ◽  
Technical Note ◽  
Distribution Functions ◽  
Full Data ◽  
Data Set ◽  
Upper Troposphere ◽  
Tropopause Region ◽  
Passenger Aircraft ◽  
Year 2000

Abstract. In-situ observational data on the relative humidity (RH) in the upper troposphere and lowermost stratosphere (UT/LS), or tropopause region, respectively, collected aboard civil passenger aircraft in the MOZAIC (Measurements of OZone, water vapour, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft) programme were reanalysed for the period 2000 to 2009. Previous analyses of probability distribution functions (PDF) of upper troposphere humidity (UTH) data from MOZAIC observations from year 2000 and later indicated a bias of UTH data towards higher RH values compared to data of the period 1994 to 1999. As a result, PDF of UTH data show a substantial fraction of observations above 100% relative humidity with respect to liquid water (RHliquid), which is not possible from thermodynamical principles. An in-depth reanalysis of the data set recovered a calibration artefact from year 2000 on, while data of the previous period from 1994 to 1999 were found to be correct. The full data set for 2000–2009 was reanalysed applying the adjusted calibration procedure. Applied correction schemes and a revised error analysis are presented along with the reanalysed PDF of RHliquid and RHice.

scholarly journals Bioclimatic traits in statistical properties of daily photosynthetically active radiation

2020 ◽  
Author(s):  
Estefanía Muñoz ◽  
Andrés Ochoa
Keyword(s):  
Spectral Band ◽  
Distribution Functions ◽  
Dry Forest ◽  
Spectral Irradiance ◽  
High Dispersion ◽  
Data Set ◽  
Tropical Regions ◽  
Clear Sky ◽  
Life Zone ◽  
Low Dispersion

Abstract. In this paper, we present a methodology to analyze the stochastic component of daily solar radiation at the earth's surface in the photosynthetically active spectral band. Extraterrestrial solar spectral irradiance from the SOLID project and in situ observed PAR from the FLUXNET data set are used to calculate daily time series of the clearness and clear-sky indices for 28 FLUXNET sites around the world for 1978–2014. We found that the shape of the probability distribution functions of the clearness and clear-sky indices exhibit a spatial pattern related to the Köppen climate classification and the Holdridge life zones. According to the Köppen classification, oceanic, humid continental, and Mediterranean climates show bimodal distributions; semi-arid, temperate, subtropical, and desert climates show unimodal distributions with high dispersion; and tropical climates show unimodal distributions with low dispersion. Moreover, according to the Holdridge triangle, sites with bimodal distributions are concentrated in moist and wet forest life zones located in boreal and cool temperate regions and sub-humid and humid provinces. Unimodal distributions with high dispersion are concentrated in the moist forest life zone in subtropical and tropical regions and humid province; and unimodal distributions with low dispersion are concentrated in dry forest, very dry forest, and thorn woodland in tropical and subtropical regions between arid and subhumid humidity provinces.

scholarly journals Statistical analysis of water vapour and ozone in the UT/LS observed during SPURT and MOZAIC

2008 ◽  
Vol 8 (4) ◽  
pp. 12561-12594
Author(s):  
A. Kunz ◽  
C. Schiller ◽  
F. Rohrer ◽  
H. G. J. Smit ◽  
P. Nedelec ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Water Vapour ◽  
Trace Gases ◽  
Distribution Functions ◽  
Variance Analysis ◽  
Trace Gas ◽  
Data Sets ◽  
Data Set ◽  
Atmospheric Processes ◽  
Passenger Aircraft

Abstract. A statistical analysis for the comparability of water (H2O) and ozone (O3) data sets sampled during the SPURT aircraft campaigns and the MOZAIC passenger aircraft flights is presented. The Kolmogoroff–Smirnoff test reveals that the distribution functions from SPURT and MOZAIC trace gases differ from each other with a confidence of 95%. A variance analysis shows a different variability character in both trace gas data sets. While the SPURT data only contain atmospheric processes variable on a diurnal or synoptical timescale, MOZAIC data also reveal processes, which vary on inter-seasonal and seasonal timescales. The SPURT data set does not represent the full MOZAIC H2O variance in the UT/LS for climatological investigations, whereas the variance of O3 is much better represented. SPURT H2O data are better suited in the stratosphere, where the MOZAIC RH sensor looses its sensitivity.

scholarly journals Analysis of accurate <sup>13</sup>C and <sup>18</sup>O isotope measurements of CO<sub>2</sub> in CARIBIC aircraft air samples from the tropical troposphere, and the upper troposphere/lowermost stratosphere

2010 ◽  
Vol 10 (3) ◽  
pp. 5999-6057
Author(s):  
S. S. Assonov ◽  
C. A. M. Brenninkmeijer ◽  
T. J. Schuck ◽  
P. Taylor
Keyword(s):  
Atmospheric Chemistry ◽  
Hydrological Cycle ◽  
Atmospheric Transport ◽  
Global Scale ◽  
Data Sets ◽  
Free Troposphere ◽  
Data Set ◽  
Upper Troposphere ◽  
Passenger Aircraft ◽  
Good Agreement

Abstract. The project CARIBIC (http://caribic-atmospheric.com) aims to study atmospheric chemistry and transport by regularly measuring many compounds in the free troposphere (FT) and the upper troposphere/lowermost stratosphere (UT/LMS) by using passenger aircraft. Here CO2 concentrations and highly accurate isotope results are presented in detail together with supporting trace gas data. 509 CARIBIC-2 samples (highest precision and accuracy δ13C(CO2) and δ18O(CO2) data) from June 2007 until March 2009, together with CARIBIC-1 samples (flights between November 1999 and April 2002, 350 samples in total, 270 for NH, mostly δ13C(CO2) data) give a fairly extensive, unique data set for the NH free troposphere and the UT/LMS region. To compare data from different years a de-trending is applied. In the UT/LMS region δ13C(CO2), δ18O(CO2) and CO2 are found to correlate well with stratospheric tracers, in particular N2O. These correlations are in good agreement with current understanding of stratospheric circulation. δ18O(CO2) appears to be a useful, hitherto unused, tracer of atmospheric transport in the UT/LMS region. By filtering out the LMS data (based on N2O distribution), the isotope variations for the free and upper troposphere are obtained. These show however little latitudinal gradient, if any, and are in good agreement with the data of selected NOAA stations in NH tropics. Correlations between δ13C(CO2) and CO2 are observed both within single flight(s) covering long distances and for certain seasons. The overall variability in de-trended δ13C(CO2) and CO2 for CARIBIC-1 and CARIBIC-2 are similar and basically agree with each other, which also underscores the high quality of measurement. Based on all correlations, we discuss that CO2 distribution in the NH FT and UT (at CARIBIC flight routes) is regulated by uplift and pole-wards transport of tropical air up to approximately 50° N. The main reasons for variability of signals in FT and UT (which is larger for the high spatial resolution sampling during CARIBIC-2) is mixing of different tropospheric air masses affected by CO2 sources and sinks. The effect of stratospheric flux appears to be limited. All in all it is demonstrated that CARIBIC produced new important and reliable data sets for little explored regions of the atmosphere. A logical next step will be global scale modeling of δ13C and especially δ18O, which is linked to the hydrological cycle.

Experimental investigation and modelling of light scattering in a-Si:H solar cells deposited on glass/ZnO:Al substrates

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Krc ◽  
M. Zeman ◽  
O. Kluth ◽  
F. Smole ◽  
M. Topic
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Solar Cells ◽  
Angular Distribution ◽  
Light Scattering ◽  
Optical Model ◽  
Distribution Functions ◽  
Interface Roughness ◽  
Scattering Parameters ◽  
Good Agreement

AbstractThe descriptive scattering parameters, haze and angular distribution functions of textured ZnO:Al transparent conductive oxides with different surface roughness are measured. An approach to determine the scattering parameters of all internal interfaces in p-i-n a-Si:H solar cells deposited on the glass/ZnO:Al substrates is presented. Using the determined scattering parameters as the input parameters of the optical model, a good agreement between the measured and simulated quantum efficiencies of the p-i-n a-Si:H solar cells with different interface roughness is achieved.

scholarly journals Do galactic bars depend on environment?: an information theoretic analysis of Galaxy Zoo 2

2020 ◽  
Vol 501 (1) ◽  
pp. 994-1001
Author(s):  
Suman Sarkar ◽  
Biswajit Pandey ◽  
Snehasish Bhattacharjee
Keyword(s):  
Spatial Distribution ◽  
Mutual Information ◽  
Local Density ◽  
Statistical Significance ◽  
Distribution Functions ◽  
Cumulative Distribution ◽  
Host Galaxy ◽  
Data Sets ◽  
Data Set ◽  
Information Theoretic

ABSTRACT We use an information theoretic framework to analyse data from the Galaxy Zoo 2 project and study if there are any statistically significant correlations between the presence of bars in spiral galaxies and their environment. We measure the mutual information between the barredness of galaxies and their environments in a volume limited sample (Mr ≤ −21) and compare it with the same in data sets where (i) the bar/unbar classifications are randomized and (ii) the spatial distribution of galaxies are shuffled on different length scales. We assess the statistical significance of the differences in the mutual information using a t-test and find that both randomization of morphological classifications and shuffling of spatial distribution do not alter the mutual information in a statistically significant way. The non-zero mutual information between the barredness and environment arises due to the finite and discrete nature of the data set that can be entirely explained by mock Poisson distributions. We also separately compare the cumulative distribution functions of the barred and unbarred galaxies as a function of their local density. Using a Kolmogorov–Smirnov test, we find that the null hypothesis cannot be rejected even at $75{{\ \rm per\ cent}}$ confidence level. Our analysis indicates that environments do not play a significant role in the formation of a bar, which is largely determined by the internal processes of the host galaxy.

Agreement and reliability of magnetic, angular rate, and gravity (MARG) sensors to assess multiple body segment’s external loads during off-road running

2021 ◽  
pp. 175433712199698
Author(s):  
Daniel Rojas-Valverde ◽  
José Pino-Ortega ◽  
Rafael Timón ◽  
Randall Gutiérrez-Vargas ◽  
Braulio Sánchez-Ureña ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Angular Rate ◽  
Wearable Sensors ◽  
Intraclass Correlation ◽  
Principal Component ◽  
Test Reliability ◽  
Data Set ◽  
Body Segments ◽  
External Loads ◽  
Good Agreement

The extensive use of wearable sensors in sport medicine, exercise medicine, and health has increased the interest in their study. That is why it is necessary to test these technologies’ efficiency, effectiveness, agreement, and reliability in different settings. Consequently, the purpose of this article was to analyze the magnetic, angular rate, and gravity (MARG) sensor’s test-retest agreement and reliability when assessing multiple body segments’ external loads during off-road running. A total of 18 off-road runners (38.78 ± 10.38 years, 73.24 ± 12.6 kg, 172.17 ± 9.48 cm) ran two laps (1st and 2nd Lap) of a 12 km circuit wearing six MARG sensors. The sensors were attached to six different body segments: left (MPLeft) and right (MPRight) malleolus peroneus, left (VLLeft) and right (VLRight) vastus lateralis, lumbar (L1-L3), and thorax (T2-T4) using a special neoprene suit. After a principal component analysis (PCA) was performed, the total data set variance of all body segments was represented by 44.08%–70.64% for the 1st PCA factor considering two variables, Player LoadRT and Impacts, on L1-L3, respectively. These two variables were chosen among three total accelerometry-based external load indicators (ABELIs) to perform the agreement and reliability tests due to their relevance based on PCAs for each body segment. There were no significant differences between laps in the Player LoadRT or Impacts ( p > 0.05, trivial). The intraclass correlation and lineal correlation showed a substantial to almost perfect over-time test consistency assessed via reliability in both Player LoadRT and Impacts. Bias and t-test assessments showed good agreement between Laps. It can be concluded that MARGs sensors offer significant test re-test reliability and good agreement when assessing off-road kinematics in the six different body segments.

Disorientations in dislocation structures: Formation and spatial correlation

2002 ◽  
Vol 17 (9) ◽  
pp. 2433-2441 ◽  
Author(s):  
Wolfgang Pantleon
Keyword(s):  
Plastic Deformation ◽  
Spatial Correlation ◽  
Distribution Functions ◽  
Scaling Behavior ◽  
Dislocation Dynamics ◽  
Slip Systems ◽  
Experimental Findings ◽  
Good Agreement

During plastic deformation, dislocation boundaries are formed and orientation differences across them arise. Two different causes lead to the formation of two kinds of deformation-induced boundaries: a statistical trapping of dislocations in incidental dislocation boundaries and a difference in the activation of slip systems on both sides of geometrically necessary boundaries. On the basis of these mechanisms, the occurrence of disorientations across both types of dislocation boundaries is modeled by dislocation dynamics. The resulting evolution of the disorientation angles with strain is in good agreement with experimental observations. The theoretically obtained distribution functions for the disorientation angles describe the experimental findings well and explain their scaling behavior. The model also predicts correlations between disorientations in neighboring boundaries, and evidence for their existence is presented.

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