Test of in situ measurements of atmospheric aerosols and trace gases by long path transmission spectroscopy

1990 ◽  
Vol 21 ◽  
pp. S193-S196 ◽  
Author(s):  
J. Notholt ◽  
F. Raes
Keyword(s):  
Atmospheric Aerosols ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Transmission Spectroscopy

In situ measurements of microphysical properties and trace gases in two cumulonimbus anvils over western Europe

1999 ◽  
Vol 104 (D10) ◽  
pp. 12221-12226 ◽  
Author(s):  
Johan Ström ◽  
Horst Fischer ◽  
Jos Lelieveld ◽  
Franz Schröder
Keyword(s):  
Western Europe ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Microphysical Properties

scholarly journals An indirect-calibration method for non-target quantification of trace gases applied to a time series of fourth-generation synthetic halocarbons at the Taunus Observatory (Germany)

2021 ◽  
Vol 14 (6) ◽  
pp. 4669-4687
Author(s):  
Fides Lefrancois ◽  
Markus Jesswein ◽  
Markus Thoma ◽  
Andreas Engel ◽  
Kieran Stanley ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Trace Gases ◽  
Mass Range ◽  
Calibration Method ◽  
In Situ Measurements ◽  
Atmospheric Composition ◽  
Fourth Generation ◽  
Calibration Gas ◽  
Tof Ms

Abstract. Production and use of many synthetic halogenated trace gases are regulated internationally due to their contribution to stratospheric ozone depletion or climate change. In many applications they have been replaced by shorter-lived compounds, which have become measurable in the atmosphere as emissions increased. Non-target monitoring of trace gases rather than targeted measurements of well-known substances is needed to keep up with such changes in the atmospheric composition. We regularly deploy gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOF-MS) for analysis of flask air samples and in situ measurements at the Taunus Observatory, a site in central Germany. TOF-MS acquires data over a continuous mass range that enables a retrospective analysis of the dataset, which can be considered a type of digital air archive. This archive can be used if new substances come into use and their mass spectrometric fingerprint is identified. However, quantifying new replacement halocarbons can be challenging, as mole fractions are generally low, requiring high measurement precision and low detection limits. In addition, calibration can be demanding, as calibration gases may not contain sufficiently high amounts of newly measured substances or the amounts in the calibration gas may have not been quantified. This paper presents an indirect data evaluation approach for TOF-MS data, where the calibration is linked to another compound which could be quantified in the calibration gas. We also present an approach to evaluate the quality of the indirect calibration method, select periods of stable instrument performance and determine well suited reference compounds. The method is applied to three short-lived synthetic halocarbons: HFO-1234yf, HFO-1234ze(E), and HCFO-1233zd(E). They represent replacements for longer-lived hydrofluorocarbons (HFCs) and exhibit increasing mole fractions in the atmosphere. The indirectly calibrated results are compared to directly calibrated measurements using data from TOF-MS canister sample analysis and TOF-MS in situ measurements, which are available for some periods of our dataset. The application of the indirect calibration method on several test cases can result in uncertainties of around 6 % to 11 %. For hydro(chloro-)fluoroolefines (denoted H(C)FOs), uncertainties up to 23 % are achieved. The indirectly calculated mole fractions of the investigated H(C)FOs at Taunus Observatory range between measured mole fractions at urban Dübendorf and Jungfraujoch stations in Switzerland.

Das ACTRIS-Kalibrierzentrum für Stickoxid-Messungen am Forschungszentrum Jülich

2021 ◽  
Author(s):  
Max Gerrit Adam ◽  
Robert Wegener ◽  
Franz Rohrer ◽  
Ralf Tillmann ◽  
Astrid Kiendler-Scharr ◽  
...  
Keyword(s):  
Phase Shift ◽  
Diode Laser ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Tunable Diode Laser ◽  
Research Infrastructure ◽  
Aerosol Cloud ◽  
Reactive Trace Gases

<p>Langzeitmessungen der atmosphärischen Zusammensetzung sind von zentraler Bedeutung, um die Atmosphärenchemie und den Klimawandel zu verstehen. ACTRIS (Aerosol, Cloud and Trace Gases Research Infrastructure) hat sich zum Ziel gesetzt, ein europaweites Netzwerk von Beobachtungsstationen aufzubauen, die qualitativ hochwertige Daten und Informationen zu kurzlebigen atmosphärischen Bestandteilen liefern und für Nutzer auf der ganzen Welt offen zugänglich machen. Stickstoffmonoxid (NO) und Stickstoffdioxid (NO<sub>2</sub>), die sogenannten Stickoxide (NO<sub>x</sub>), spielen eine Schlüsselrolle in der Atmosphärenchemie, da sie zur Bildung von troposphärischem Ozon, Smog und saurem Regen beitragen. Darüber hinaus ist die kurz- und langfristige Exposition mit NO<sub>2</sub> mit negativen Auswirkungen auf das menschliche Atmungssystem in Verbindung gebracht worden. Die Hauptquellen von NO<sub>x</sub> in bewohnten Gebieten sind Verbrennungsprozesse, z.B. von Fahrzeugen und bei industriellen Aktivitäten. NO<sub>x</sub>-Messungen werden derzeit meist indirekt über Chemilumineszenz-Instrumente durchgeführt, die Korrekturen für Feuchte und Ozon erfordern. Jüngste technologische Fortschritte (z. B. Cavity Attenuated Phase Shift, CAPS, oder Tunable Diode Laser Systeme) erlauben die direkte Detektion von NO<sub>x</sub>-Komponenten, was Interferenzen vermeidet, die durch die Umwandlung von NO<sub>2</sub> in NO hervorgerufen werden. Messvergleiche zeigen aber, dass auch hier neben bekannten Problemen wie Reaktionen in den Einlassleitungen auch unerwartete Artefakte beobachtet werden können. Messvergleiche aber zeigen auch hier, dass neben bekannten Problemen wie Reaktionen in den Einlassleitungen auch unerwartete auftreten können. Um genaue und präzise NO<sub>x</sub> Messungen mit einer Vielzahl von NO<sub>x</sub>-Messsystemen in verschiedenen Stationen sicherzustellen, müssen neben der Standardisierung von Messprotokollen und Kalibrierungsverfahren auch an zentraler Stelle durch Messvergleiche und Auditierungen Unterschiede der verschiedenen Messverfahren dokumentiert werden.</p> <p>ACTRIS setzt sich aus central facilities (CFs) und national facilities (NFs) zusammen. Die NFs bilden den explorativen und beobachtenden Teil der Forschungsinfrastruktur. Die CFs sind von grundlegender Bedeutung für die Bereitstellung von harmonisierten und hochpräzisen Daten und stellen eine Vielzahl von Dienstleistungen zur Verfügung. Eines der CFs ist das Reactive Trace Gases In Situ Measurements (CiGas), das für die Überwachung der Datenqualität reaktiver Spurengase verantwortlich ist. Für die Qualitätssicherung (QA) und Qualitätskontrolle (QC) der Stickoxidmessungen an den NFs innerhalb von CiGas ist das Forschungszentrum Jülich (FZJ) zuständig, das auch das World Calibration Center (WCC) für Stickoxide im Global Atmosphere Watch (GAW) Netzwerk beheimatet. Seine Aufgaben umfassen i) die Verbindung von Spurengasmessungen von ACTRIS mit denen anderer Netzwerke, ii) die Beratung und Organisation von Schulungen, iii) die Bereitstellung von Mess- und Auswerteverfahren, iv) das Labelling und die Auditierung von NFs, v) die Implementierung neuer wissenschaftlicher und technologischer Entwicklungen.</p> <p>Es ist vorgesehen, bis 2025 ein zertifiziertes und funktionsfähiges Netzwerk von ACTRIS-Stationen aufzubauen. Es soll der wissenschaftlichen Gemeinschaft qualitativ hochwertige Daten liefern, die die Grundlage für fundierte Entscheidungen der politischen Entscheidungsträger bilden können.</p>

In-situ measurements of atmospheric aerosols by using Integrating Nephelometer over a semi-arid station, southern India

2014 ◽  
Vol 86 ◽  
pp. 228-240 ◽  
Author(s):  
K. Rama Gopal ◽  
S.Md. Arafath ◽  
A.P. Lingaswamy ◽  
G. Balakrishnaiah ◽  
S. Pavan Kumari ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
In Situ Measurements ◽  
Southern India ◽  
Integrating Nephelometer ◽  
Semi Arid

scholarly journals Deep convective injection of boundary layer air into the lowermost stratosphere at midlatitudes

2003 ◽  
Vol 3 (3) ◽  
pp. 739-745 ◽  
Author(s):  
H. Fischer ◽  
M. de Reus ◽  
M. Traub ◽  
J. Williams ◽  
J. Lelieveld ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Background Concentrations ◽  
Upper Troposphere ◽  
German Research ◽  
Research Aircraft ◽  
The Mediterranean

Abstract. On 22 August 2001 a measurement flight was performed with the German research aircraft FALCON from Sardinia to Crete as part of the Mediterranean Oxidant Study (MINOS). Cruising at 8.2 km, the aircraft was forced to climb to 11.2 km over the southern tip of Italy to stay clear of the anvil of a large cumulonimbus tower. During ascent into the lowermost stratosphere in-situ measurements onboard the FALCON indicated several sharp increases in the concentrations of tropospheric trace gases, e.g. CO, acetone, methanol, benzene and acetonitrile, above the anvil. During one particular event deep in the stratosphere, at O3 concentrations exceeding 200 ppv, CO increased from about 60 to 90 ppv, while the concentration of acetone and methanol increased by more than a factor of 2 (0.7 to 1.8 ppv for acetone; 0.4 to 1.4 ppv for methanol). Enhancements for the short lived species benzene are even higher, increasing from 20 pptv in the stratosphere to approx. 130 pptv. The concentrations during the event were higher than background concentrations in the upper troposphere, indicating that polluted boundary layer air was directly mixed into the lowermost stratosphere.

scholarly journals Deep convective injection of boundary layer air into the lowermost stratosphere at midlatitudes

2002 ◽  
Vol 2 (6) ◽  
pp. 2003-2019 ◽  
Author(s):  
H. Fischer ◽  
M. de Reus ◽  
M. Traub ◽  
J. Williams ◽  
J. Lelieveld ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Background Concentrations ◽  
Upper Troposphere ◽  
German Research ◽  
Research Aircraft ◽  
The Mediterranean

Abstract. On 22 August 2001 a measurement flight was performed with the German research aircraft FALCON from Sardinia to Crete as part of the Mediterranean Oxidant Study (MINOS). Cruising at 8.2 km, the aircraft was forced to climb to 11.2 km over the southern tip of Italy to stay clear of the anvil of a large cumulonimbus tower. During ascent into the lowermost stratosphere in-situ measurements onboard the FALCON indicated several sharp increases in the concentrations of tropospheric trace gases, e.g. CO, acetone, methanol, benzene and acetonitrile, above the anvil. During one particular event deep in the stratosphere, at O3 concentrations exceeding 200 ppv, CO increased from about 60 to 90 ppv, while the concentration of acetone and methanol increased by more than a factor of 2 (0.7 to 1.8 ppv for acetone; 0.4 to 1.4 ppv for methanol). Enhancements for the short lived species benzene are even higher, increasing from 20 pptv in the stratosphere to approx. 130 pptv. The concentrations during the event were higher than background concentrations in the upper troposphere, indicating that polluted boundary layer air was directly mixed deep into the lowermost stratosphere.

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