scholarly journals Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

2010 ◽  
Vol 10 (2) ◽  
pp. 2769-2808
Author(s):  
E. Remsberg ◽  
M. Natarajan ◽  
T. Marshall ◽  
L. L. Gordley ◽  
R. E. Thompson ◽  
...  
Keyword(s):  
Water Vapor ◽  
Nitric Acid ◽  
Nitrogen Dioxide ◽  
Theoretical Calculations ◽  
Oxides Of Nitrogen ◽  
Polar Night ◽  
Chemical Effects ◽  
Satellite Sensors ◽  
Precision And Accuracy

Abstract. The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) nitric acid (HNO3) and nitrogen dioxide (NO2) profiles and distributions of 1978/1979 is described after their processing with an updated, Version 6 (V6) algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO3 profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5) profiles, except in the upper stratosphere where the interfering effects of CO2 are accounted for better with V6. The accuracy of the retrieved V6 NO2 is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO3/NO2 ratio, day-to-night NO2 ratio, and with estimates of the production of NO2 in the mesosphere and its descent to the upper stratosphere during polar night. The improved precisions and more frequent retrievals of the profiles along the LIMS orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be examined quantitatively throughout the stratosphere with the LIMS V6 data, and that the findings will be more compatible with those obtained from measurements of the same species from subsequent satellite sensors.

scholarly journals Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

2010 ◽  
Vol 10 (10) ◽  
pp. 4741-4756 ◽  
Author(s):  
E. Remsberg ◽  
M. Natarajan ◽  
B. T. Marshall ◽  
L. L. Gordley ◽  
R. E. Thompson ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Nitrogen Dioxide ◽  
Theoretical Calculations ◽  
Spin Splitting ◽  
Oxides Of Nitrogen ◽  
Polar Night ◽  
Chemical Effects ◽  
Satellite Sensors ◽  
Precision And Accuracy

Abstract. The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) nitric acid (HNO3) and nitrogen dioxide (NO2) profiles and distributions of 1978/1979 are described after their processing with an updated, Version 6 (V6) algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO3 profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5) profiles, except in the upper stratosphere where the interfering effects of CO2 are accounted for better with V6. The accuracy of the retrieved V6 NO2 is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO3/NO2 ratio, day-to-night NO2 ratio, and with estimates of the production of NO2 in the mesosphere and its descent to the upper stratosphere during polar night. In particular, the findings for middle and upper stratospheric NO2 should also be more compatible with those obtained from more recent satellite sensors because the effects of the spin-splitting of the NO2 lines are accounted for now with the LIMS V6 algorithm. The improved precisions and more frequent retrievals of the LIMS profiles along their orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be studied quantitatively throughout the stratosphere with the LIMS V6 data.

scholarly journals On the quality of the Nimbus 7 LIMS Version 6 water vapor profiles and distributions

2009 ◽  
Vol 9 (5) ◽  
pp. 17903-17935
Author(s):  
E. E. Remsberg ◽  
M. Natarajan ◽  
G. S. Lingenfelser ◽  
R. E. Thompson ◽  
B. T. Marshall ◽  
...  
Keyword(s):  
Water Vapor ◽  
Recent Decade ◽  
Global Scale ◽  
Field Of View ◽  
Temperature Profiles ◽  
Entry Level ◽  
Satellite Experiment ◽  
Precision And Accuracy ◽  
Individual Profiles

Abstract. This report describes the quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) water vapor (H2O) profiles of 1978/1979 that were processed with a Version 6 (V6) algorithm and archived in 2002. The V6 profiles incorporate a better knowledge of the instrument attitude for the LIMS measurements along its orbits, leading to improvements for its temperature profiles and for the registration of its water vapor radiances with pressure. As a result, the LIMS V6 zonal-mean distributions of H2O exhibit better hemispheric symmetry than was the case from the original Version 5 (V5) dataset that was archived in 1982. Estimates of the precision and accuracy of the V6 H2O profiles are developed and provided. Individual profiles have a precision of order 5% and an estimated accuracy of about 19% at 3 hPa, 14% at 10 hPa, and 26% at 50 hPa. Profile segments within about 2 km of the tropopause are often affected by emissions from clouds that appear in the finite field-of-view of the detector for the LIMS H2O channel. Zonally-averaged distributions of the LIMS V6 H2O are compared with those from the more recent Microwave Limb Sounder (MLS) satellite experiment for November, February, and May of 2004/2005. The patterns and values of their respective distributions are similar in many respects. Effects of a strengthened Brewer-Dobson circulation are indicated in the MLS distributions of the recent decade versus those of LIMS from 1978/1979. A tropical tape recorder signal is present in the 7-month time series of LIMS V6 H2O with lowest values in February 1979, and the estimated, annually-averaged "entry-level" H2O is 3.5 to 3.8 ppmv. It is judged that this historic LIMS water vapor dataset is of good quality for studies of the near global-scale chemistry and transport for pressure levels from 3 hPa to about 70 to 100 hPa.

scholarly journals A study of the chemical quality of ambient air at selected intersections in the Durban Metropolis

2003 ◽  
Author(s):  
◽  
Shalini Singh
Keyword(s):  
Nitric Oxide ◽  
Air Pollution ◽  
Nitrogen Dioxide ◽  
Ambient Air ◽  
Urban Environments ◽  
Motor Vehicles ◽  
Chemical Quality ◽  
Oxides Of Nitrogen ◽  
Combustion Processes

Motor vehicles are considered a major source of air pollution in urban environments. Nitrogen dioxide (N02) and nitric oxide (NO) which are collectively referred to as oxides of nitrogen (NOx) are formed at high temperatures during combustion processes in the engines of motor vehicles and are emitted via the exhaust into the atmosphere. Nitrogen dioxide is regarded as an irritant of the respiratory system.

scholarly journals On the quality of the Nimbus 7 LIMS Version 6 water vapor profiles and distributions

2009 ◽  
Vol 9 (23) ◽  
pp. 9155-9167 ◽  
Author(s):  
E. E. Remsberg ◽  
M. Natarajan ◽  
G. S. Lingenfelser ◽  
R. E. Thompson ◽  
B. T. Marshall ◽  
...  
Keyword(s):  
Water Vapor ◽  
Recent Decade ◽  
Global Scale ◽  
Field Of View ◽  
Temperature Profiles ◽  
Entry Level ◽  
Satellite Experiment ◽  
Precision And Accuracy ◽  
Individual Profiles

Abstract. This report describes the quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) water vapor (H2O) profiles of 1978/79 that were processed with a Version 6 (V6) algorithm and archived in 2002. The V6 profiles incorporate a better knowledge of the instrument attitude for the LIMS measurements along its orbits, leading to improvements for its temperature profiles and for the registration of its water vapor radiances with pressure. As a result, the LIMS V6 zonal-mean distributions of H2O exhibit better hemispheric symmetry than was the case from the original Version 5 (V5) dataset that was archived in 1982. Estimates of the precision and accuracy of the V6 H2O profiles are developed and provided. Individual profiles have a precision of order 5% and an estimated accuracy of about 19% at 3 hPa, 14% at 10 hPa, and 26% at 50 hPa. Profile segments within about 2 km of the tropopause are often affected by emissions from clouds that appear in the finite field-of-view of the detector for the LIMS H2O channel. Zonally-averaged distributions of the LIMS V6 H2O are compared with those from the more recent Microwave Limb Sounder (MLS) satellite experiment for November, February, and May of 2004/05. The patterns and values of their respective distributions are similar in many respects. Effects of a strengthened Brewer-Dobson circulation are indicated in the MLS distributions of the recent decade versus those of LIMS from 1978/79. A tropical tape recorder signal is present in the 7-month time series of LIMS V6 H2O with lowest values in February 1979, and the estimated, annually-averaged "entry-level" H2O is 3.5 to 3.8 ppmv. It is judged that this historic LIMS water vapor dataset is of good quality for studies of the near global-scale chemistry and transport for pressure levels from 3 hPa to about 70 to 100 hPa.

Chemical Effects and Predictive Factors in Premature Birth

2018 ◽  
Vol 69 (7) ◽  
pp. 1796-1801
Author(s):  
Adrian Neacsu ◽  
Alina Calin ◽  
Anca Daniela Braila ◽  
Dan Navolan ◽  
Mihai Dimitriu ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Premature Birth ◽  
Tissue Concentration ◽  
Premature Labor ◽  
New Born ◽  
Uterine Contractions ◽  
Chemical Effects ◽  
Equal Importance ◽  
Necrosis Factor

Premature birth is considered to be the consequence of independent alterations in the cervix and in the uterus. During labor, for full-term birth, as well as for premature birth, the cervix changes, from firm, long and closed, to soft and pliable, through a biochemical process characterized by the reshaping of the extracellular matrix and a growth of the tissue concentration of inflammatory mediators; the uterus proves an increase in contractility and sensitivity to endogenic hormones, such as oxytocin. Premature labor is associated with the premature activation of the release of cytokines in the decidua (mucosa lining uterus walls) and cervix. Interleukins IL-1 beta, IL-6, IL-8 and the alpha tumoral necrosis factor increase the production and activation of matrix metalloproteinases (MMP-1, MMP-3 and MMP-9) and of cathepsin S, which digests the collagen from the extracellular matrix of the cervix, causing the wiping and softening of the cervix. These cytokines are released by leukocytes in the myometer, leading to the production of prostaglandins and oxytocin, which stimulate uterine contractions. Therefore, the cervical shortening represented by ultrasound is believed to represent premature cervical softening. The obstetrical approach of aspects related to premature birth are based, considerably, on the prognosis expected by the obstetrician regarding the survival of the premature new-born baby, as well as the therapeutic variants to be followed. And not only survival is important, of equal importance is also the quality of life of underweight, immature new-born babies, who are considerably affected both physically, and intellectually.

Volumetric and Phase Behavior of the Nitric Acid-Nitrogen Dioxide System

1954 ◽  
Vol 46 (12) ◽  
pp. 2541-2546 ◽  
Author(s):  
W. H. Corcoran ◽  
H. H. Reamer ◽  
B. H. Sage
Keyword(s):  
Nitric Acid ◽  
Nitrogen Dioxide ◽  
Phase Behavior

scholarly journals An evaluation of the SAGE III Version 4 aerosol extinction coefficient and water vapor data products

2009 ◽  
Vol 9 (5) ◽  
pp. 22177-22222
Author(s):  
L. W. Thomason ◽  
J. R. Moore ◽  
M. C. Pitts ◽  
J. M. Zawodny ◽  
E.-W. Chiou
Keyword(s):  
Water Vapor ◽  
Extinction Coefficient ◽  
Stratospheric Aerosol ◽  
Data Sets ◽  
Aerosol Extinction ◽  
Data Products ◽  
Mean Differences ◽  
Aerosol Extinction Coefficient ◽  
Polar Ozone

Abstract. Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: SAGE II, the Polar Ozone and Aerosol Measurement (POAM III), the Halogen Occultation Experiment (HALOE), and the Microwave Limb Sounder (MLS). Since only about half of the SAGE III channels have a direct comparison with measurements by other instruments, we have employed some empirical techniques to evaluate measurements at some wavelengths. We find that the aerosol extinction coefficient measurements at 449, 520, 755, 869, and 1021 nm are reliable with accuracies and precisions on the order of 10% in the primary aerosol range of 15 to 25 km. We also believe this to be true of the aerosol measurements at 1545 nm though we cannot exclude some positive bias below 15 km. We recommend use of the 385 nm measurements above 16 km where the accuracy is on par with other aerosol channels. The 601 nm measurement is much noisier (~20%) than other channels and we suggest caution in the use of these data. We believe that the 676 nm data are clearly defective particularly above 20 km (accuracy as poor as 50%) and the precision is also low (~30%). We suggest excluding this channel under most circumstances. The SAGE III Version 4 water vapor data product appears to be high quality and is recommended for science applications in the stratosphere below 45 km. In this altitude range, the mean differences with all four corroborative data sets are no bigger than 15% and often less than 10% with exceptional agreement with POAM III and MLS. Above 45 km, it seems likely that SAGE III water vapor values are increasingly too large and should be used cautiously or avoided. We believe that SAGE III meets its preflight goal of 15% accuracy and 10% precision between 15 and 45 km. We do not currently recommend limiting the SAGE III water vapor data utility in the stratosphere by aerosol loading.

scholarly journals Impact of Diwali firework emissions on air quality of New Delhi, India during 2013-2015

MAUSAM ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 111-118
Author(s):  
SUNIL KUMAR PESHIN ◽  
PRIYANKA SINHA ◽  
AMIT BISHT
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Surface Ozone ◽  
Average Concentration ◽  
New Delhi ◽  
Oxides Of Nitrogen ◽  
Huge Amount ◽  
Awareness Campaigns ◽  
Pm10 And Pm2.5

Diwali is one of the major and most important festivals celebrated all over India which falls in the period late October to early November every year. It is associated with burning of firecrackers especially during the night of Diwali day that leads to degradation of air quality that lasts for a longer duration of time. Firecrackers on burning releases huge amount of trace gases such as NOx, CO, SO2 and O3 and huge amount of aerosols and particulate matter. The present study focuses on the influence of firecrackers  emissions on surface ozone(O3) ,oxides of nitrogen (NOx) and particulate matter (PM10 and PM2.5)concentration over the capital urban metropolis of India, New Delhi during Diwali festivity period from 2013-2015. A sharp increase is observed in surface ozone, NOx and particulate matter concentration during the Diwali day as compared to control day for 2013 to 2015 which is mainly attributed to burning of firecrackers. However the average concentration levels of the  gaseous pollutants and particulate matter (PM10 and PM2.5) on Diwali day exhibited a decline in 2015 and 2014 as compared to 2013 due to increase in  awareness campaigns among public and increased cost of firecrackers.  

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