Bruno Hoegger - Academia.edu (original) (raw)
Papers by Bruno Hoegger
Journal of Geophysical Research, 2003
The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tro... more The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tropics is provided by a 3-year record of ozone soundings from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network (http://croc.gsfc.nasa.gov/ shadoz).
Atmospheric Measurement Techniques, Mar 9, 2020
In contrast to the legacy manual method used to prepare, condition, and calibrate the electrochem... more In contrast to the legacy manual method used to prepare, condition, and calibrate the electrochemical concentration cell (ECC) ozonesonde, an automated digital calibration bench similar to one developed by MeteoSwiss at Payerne, Switzerland, was established at NASA's Wallops Flight Facility and provides reference measurements of the same ozone partial pressure as measured by the ECC. The purpose of an automated system is to condition and calibrate ECCs before launching on a balloon. Operation of the digital calibration bench is simple and real-time graphs and summaries are available to the operator; all information is archived. The parameters of interest include ozone partial pressure, airflow, temperature, background current, response, and time (real and elapsed). ECCs, prepared with 1.0 % solution of potassium iodide (KI) and full buffer, show increasing partial pressure values when compared to the reference as partial pressures increase. Differences of approximately 5-6 % are noted at 20.0 mPa. Additional tests with different concentrations revealed the Science Pump Corp. (SPC) 6A ECC with 0.5 % KI solution and one-half buffer agreed closer to the reference than the 1.0 % cells. The information gained from the automated system allows a compilation of ECC characteristics, as well as calibrations. The digital calibration bench is recommended for ECC studies as it conserves resources.
Helvetica Physica Acta, 1980
Magnetoacoustic oscillations in a Helium plasma are investigated. The plasma is strongly inhomoge... more Magnetoacoustic oscillations in a Helium plasma are investigated. The plasma is strongly inhomogeneous. The average density is ne =4-1012 cm-3, but drops to an immeasurable value near the wall. The device, in which an r-/-discharge produces this profile, is described. The results of a theoretical calculation are given. This calculation is based on a three fluid cold plasma theory and the density and temperature profile as well as the finite length of the plasma column and the length of the exciting coil is taken into account. It is shown that the experiments can only be described by this calculation, if an effective collision rate is introduced. This veff might be justified by observed fluctuations at the boundary of the plasma.
An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is... more An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is presented. Development of a computer-controlled system for preparation and calibration of the ECC is an improvement over the manual preparation method, and reduces subjectivity considerably. Preparation measurements in digital form aids analysis of the ECC before release and enhances post-flight data certification. Calibration of ozonesondes over a range of ozone concentrations between 0 mPA and 30 mPA is discussed. This presentation describes the automatic system, gives examples of calibrations. The automated system enables comparison of varying potassium iodide (KI) concentrations that should allow adjustment of earlier ozonesonde data obtained with different KT concentrations used since 1970, i.e., 2, 1.5, 1, and 0.5 percent. Preliminary results indicate ECC accuracy has a strong dependence on the electrolyte concentration and should not be considered linear with altitude.
Total ozone observations of two Dobson instruments (D15 and D101, C- and AD wavelength pair obser... more Total ozone observations of two Dobson instruments (D15 and D101, C- and AD wavelength pair observations) and of two Brewer instruments (Br40 and Br72) are currently performed at the LKO at Arosa. A quality control concept is presented in order to make best use of the large number of quasi-simultaneous measurements. The longest ozone series of the world is mainly based on the measurements of the Dobson instrument D15 (wavelength pair C). Since the last years D15 has suffered from instrumental problems. The transformation of the longterm series to the measurements of D101(AD) is described.
Helvetica Physica Acta, 1972
The first view of stratospheric and tropospheric ozone variability in the southern hemisphere tro... more The first view of stratospheric and tropospheric ozone variability in the southern hemisphere tropics is provided by a 3-year, 10-site record of ozone soundings from the Southern Hemisphere ADditional OZonesondes (SHADOZ) network: < htip://code916. gsfc.nasa.qov/Data_services/shadoz>. Observations covering i998-2000 were made over Ascension Island; Nairobi, Kenya; Irene, South Africa; R6union Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Crist6bal, Galapagos; Natal, Brazil. Total, stratospheric and tropospheric column ozone amounts usually peak between August and November and are lowest in the first half of the year. Other features are a persistent zonal wave-one pattern in total (and tropospheric) column ozone and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. The wave-one pattern refers to a greater concentration of free tropospheric ozone over the Atlantic than the Pacific and appears to be associated with tropical general circulatio...
Atmospheric Measurement Techniques Discussions, 2019
In contrast to the legacy manual method used to prepare, condition, and calibrate the Electrochem... more In contrast to the legacy manual method used to prepare, condition, and calibrate the Electrochemical Concentration Cell (ECC) ozonesonde an automated digital calibration bench similar to one developed by MeteoSwiss at Payerne, Switzerland was established at NASA's Wallops Flight Facility and provides reference measurements of the same ozone partial pressure as measured by the ECC. The purpose of an automated system is to condition and calibrate ECC cells before launching on a balloon. Operation of the digital calibration bench is simple and real-time graphs and summaries are available to the operator; all information is archived. The parameters of interest include ozone partial pressure, airflow, temperature, background current, response, and time (real and elapsed). ECC cells, prepared with 1.0 percent solution of potassium iodide (KI) and full buffer, show increasing partial pressure values when compared to the reference as partial pressures increase. Differences of approximately 5-6 percent are noted at 200 nb. Additional tests with different concentrations revealed the Science Pump Corp (SPC) 6A ECC with 0.5 percent KI solution and one-half buffer agreed closer to the reference than the 1.0 percent cells, this is in agreement with results of multi-sonde comparisons obtained during BESOS. The information gained from the automated system allows a compilation of ECC cell characteristics, as well as calibrations. The digital calibration bench is recommended for ECC studies as it conserves resources.
The first climatological overview of total, stratospheric and tropospheric ozone in the southern ... more The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere Additional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Campaign data were collected on a trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approx. 7 hPa and relative humidity to approx. 200 hPa, reside at: <http://code916.gsfc.nasa.nov/Data_services/shadoz>. SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone. Prominent features are highly variable tropospheric ozone and a zonal wave-one pattern in total (and tropospheric) colum...
An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is... more An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is presented. Development of a computer-controlled system for preparation and calibration of the ECC is an improvement over the manual preparation method, and reduces subjectivity considerably. Preparation measurements in digital form aids analysis of the ECC before release and enhances post-flight data certification. Calibration of ozonesondes over a range of ozone concentrations between 0 mPA and 30 mPA is discussed. This presentation describes the automatic system and gives examples of calibrations. The automated system enables comparison of varying potassium iodide (KI) concentrations that should allow adjustment of earlier ozonesonde data obtained with different KI concentrations used since 1970, i.e., 2, 1.5, 1, and 0.5 percent. Preliminary results indicate ECC accuracy has a strong dependence on the electrolyte concentration and should not be considered linear with altitude.
Physics Letters A, 1981
Strong damping of the magnetoacoustic resonance, excited with moderate rf power in a low-density ... more Strong damping of the magnetoacoustic resonance, excited with moderate rf power in a low-density helium and argon plasma is investigated. Enhanced absorption of the wave and higher turbulence is observed wiht increasing rf power.
Plasma Physics, 1983
Anomalous attenuation of magnetosonic oscillations driven in an RF-plasma and its dependence on t... more Anomalous attenuation of magnetosonic oscillations driven in an RF-plasma and its dependence on the observed low-frequency density fluctuations are investigated. The fluctuations are identified by digital spectral analysis technique as unstable collisional drift modes leading to drift wave turbulence. A dielectric tensor accounting for the anisotropic turbulence is given and the anomalous attenuation of the externally driven oscillations is explained by the drift wave turbulence. The experiments were performed in a linear device. Typical plasma parameters are: mean electron density ne=1.5*1012 cm-3, electron temperature Te=2.5 eV, magnetic field B0=2 kG, filling gas pressure p0=3.10-4 torr argon.
International Journal of Mass Spectrometry and Ion Physics, 1974
A novel type of ion source was desigued and constructed for studies of chemical ionization proces... more A novel type of ion source was desigued and constructed for studies of chemical ionization processes, using low energy ions produced from inorganic gases in a high frequency flow discharge. An adapted flowing afterglow system replaces the conventiona eIectron bombardment device. Argon ions in high concentration from the downstream region of the afterglow react in direct ion-molecule reactions with the reagent gas introduced through an inlet port (Ar' +H2-* ArH* + H) or by efficient charge transfer reactions (Ar+ + H,O + H,O' + Ar) to produce a high number of reagent ions. Samples of different organic compounds were introduced through a sample inlet orifice and their chemical ionization spectra recorded with a quadrupole rn<ass spectrometer
Physics Letters A, 1981
ABSTRACT
Zeitschrift für Naturforschung A, 1971
Zeitschrift für angewandte Mathematik und Physik ZAMP, 1970
Zeitschrift für angewandte Mathematik und Physik ZAMP, 1978
Journal of Geophysical Research, 2003
The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tro... more The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tropics is provided by a 3-year record of ozone soundings from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network (http://croc.gsfc.nasa.gov/ shadoz).
Atmospheric Measurement Techniques, Mar 9, 2020
In contrast to the legacy manual method used to prepare, condition, and calibrate the electrochem... more In contrast to the legacy manual method used to prepare, condition, and calibrate the electrochemical concentration cell (ECC) ozonesonde, an automated digital calibration bench similar to one developed by MeteoSwiss at Payerne, Switzerland, was established at NASA's Wallops Flight Facility and provides reference measurements of the same ozone partial pressure as measured by the ECC. The purpose of an automated system is to condition and calibrate ECCs before launching on a balloon. Operation of the digital calibration bench is simple and real-time graphs and summaries are available to the operator; all information is archived. The parameters of interest include ozone partial pressure, airflow, temperature, background current, response, and time (real and elapsed). ECCs, prepared with 1.0 % solution of potassium iodide (KI) and full buffer, show increasing partial pressure values when compared to the reference as partial pressures increase. Differences of approximately 5-6 % are noted at 20.0 mPa. Additional tests with different concentrations revealed the Science Pump Corp. (SPC) 6A ECC with 0.5 % KI solution and one-half buffer agreed closer to the reference than the 1.0 % cells. The information gained from the automated system allows a compilation of ECC characteristics, as well as calibrations. The digital calibration bench is recommended for ECC studies as it conserves resources.
Helvetica Physica Acta, 1980
Magnetoacoustic oscillations in a Helium plasma are investigated. The plasma is strongly inhomoge... more Magnetoacoustic oscillations in a Helium plasma are investigated. The plasma is strongly inhomogeneous. The average density is ne =4-1012 cm-3, but drops to an immeasurable value near the wall. The device, in which an r-/-discharge produces this profile, is described. The results of a theoretical calculation are given. This calculation is based on a three fluid cold plasma theory and the density and temperature profile as well as the finite length of the plasma column and the length of the exciting coil is taken into account. It is shown that the experiments can only be described by this calculation, if an effective collision rate is introduced. This veff might be justified by observed fluctuations at the boundary of the plasma.
An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is... more An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is presented. Development of a computer-controlled system for preparation and calibration of the ECC is an improvement over the manual preparation method, and reduces subjectivity considerably. Preparation measurements in digital form aids analysis of the ECC before release and enhances post-flight data certification. Calibration of ozonesondes over a range of ozone concentrations between 0 mPA and 30 mPA is discussed. This presentation describes the automatic system, gives examples of calibrations. The automated system enables comparison of varying potassium iodide (KI) concentrations that should allow adjustment of earlier ozonesonde data obtained with different KT concentrations used since 1970, i.e., 2, 1.5, 1, and 0.5 percent. Preliminary results indicate ECC accuracy has a strong dependence on the electrolyte concentration and should not be considered linear with altitude.
Total ozone observations of two Dobson instruments (D15 and D101, C- and AD wavelength pair obser... more Total ozone observations of two Dobson instruments (D15 and D101, C- and AD wavelength pair observations) and of two Brewer instruments (Br40 and Br72) are currently performed at the LKO at Arosa. A quality control concept is presented in order to make best use of the large number of quasi-simultaneous measurements. The longest ozone series of the world is mainly based on the measurements of the Dobson instrument D15 (wavelength pair C). Since the last years D15 has suffered from instrumental problems. The transformation of the longterm series to the measurements of D101(AD) is described.
Helvetica Physica Acta, 1972
The first view of stratospheric and tropospheric ozone variability in the southern hemisphere tro... more The first view of stratospheric and tropospheric ozone variability in the southern hemisphere tropics is provided by a 3-year, 10-site record of ozone soundings from the Southern Hemisphere ADditional OZonesondes (SHADOZ) network: < htip://code916. gsfc.nasa.qov/Data_services/shadoz>. Observations covering i998-2000 were made over Ascension Island; Nairobi, Kenya; Irene, South Africa; R6union Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Crist6bal, Galapagos; Natal, Brazil. Total, stratospheric and tropospheric column ozone amounts usually peak between August and November and are lowest in the first half of the year. Other features are a persistent zonal wave-one pattern in total (and tropospheric) column ozone and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. The wave-one pattern refers to a greater concentration of free tropospheric ozone over the Atlantic than the Pacific and appears to be associated with tropical general circulatio...
Atmospheric Measurement Techniques Discussions, 2019
In contrast to the legacy manual method used to prepare, condition, and calibrate the Electrochem... more In contrast to the legacy manual method used to prepare, condition, and calibrate the Electrochemical Concentration Cell (ECC) ozonesonde an automated digital calibration bench similar to one developed by MeteoSwiss at Payerne, Switzerland was established at NASA's Wallops Flight Facility and provides reference measurements of the same ozone partial pressure as measured by the ECC. The purpose of an automated system is to condition and calibrate ECC cells before launching on a balloon. Operation of the digital calibration bench is simple and real-time graphs and summaries are available to the operator; all information is archived. The parameters of interest include ozone partial pressure, airflow, temperature, background current, response, and time (real and elapsed). ECC cells, prepared with 1.0 percent solution of potassium iodide (KI) and full buffer, show increasing partial pressure values when compared to the reference as partial pressures increase. Differences of approximately 5-6 percent are noted at 200 nb. Additional tests with different concentrations revealed the Science Pump Corp (SPC) 6A ECC with 0.5 percent KI solution and one-half buffer agreed closer to the reference than the 1.0 percent cells, this is in agreement with results of multi-sonde comparisons obtained during BESOS. The information gained from the automated system allows a compilation of ECC cell characteristics, as well as calibrations. The digital calibration bench is recommended for ECC studies as it conserves resources.
The first climatological overview of total, stratospheric and tropospheric ozone in the southern ... more The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere Additional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Campaign data were collected on a trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approx. 7 hPa and relative humidity to approx. 200 hPa, reside at: <http://code916.gsfc.nasa.nov/Data_services/shadoz>. SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone. Prominent features are highly variable tropospheric ozone and a zonal wave-one pattern in total (and tropospheric) colum...
An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is... more An automated method for preparation of the electrochemical concentration cell (ECC) ozonesonde is presented. Development of a computer-controlled system for preparation and calibration of the ECC is an improvement over the manual preparation method, and reduces subjectivity considerably. Preparation measurements in digital form aids analysis of the ECC before release and enhances post-flight data certification. Calibration of ozonesondes over a range of ozone concentrations between 0 mPA and 30 mPA is discussed. This presentation describes the automatic system and gives examples of calibrations. The automated system enables comparison of varying potassium iodide (KI) concentrations that should allow adjustment of earlier ozonesonde data obtained with different KI concentrations used since 1970, i.e., 2, 1.5, 1, and 0.5 percent. Preliminary results indicate ECC accuracy has a strong dependence on the electrolyte concentration and should not be considered linear with altitude.
Physics Letters A, 1981
Strong damping of the magnetoacoustic resonance, excited with moderate rf power in a low-density ... more Strong damping of the magnetoacoustic resonance, excited with moderate rf power in a low-density helium and argon plasma is investigated. Enhanced absorption of the wave and higher turbulence is observed wiht increasing rf power.
Plasma Physics, 1983
Anomalous attenuation of magnetosonic oscillations driven in an RF-plasma and its dependence on t... more Anomalous attenuation of magnetosonic oscillations driven in an RF-plasma and its dependence on the observed low-frequency density fluctuations are investigated. The fluctuations are identified by digital spectral analysis technique as unstable collisional drift modes leading to drift wave turbulence. A dielectric tensor accounting for the anisotropic turbulence is given and the anomalous attenuation of the externally driven oscillations is explained by the drift wave turbulence. The experiments were performed in a linear device. Typical plasma parameters are: mean electron density ne=1.5*1012 cm-3, electron temperature Te=2.5 eV, magnetic field B0=2 kG, filling gas pressure p0=3.10-4 torr argon.
International Journal of Mass Spectrometry and Ion Physics, 1974
A novel type of ion source was desigued and constructed for studies of chemical ionization proces... more A novel type of ion source was desigued and constructed for studies of chemical ionization processes, using low energy ions produced from inorganic gases in a high frequency flow discharge. An adapted flowing afterglow system replaces the conventiona eIectron bombardment device. Argon ions in high concentration from the downstream region of the afterglow react in direct ion-molecule reactions with the reagent gas introduced through an inlet port (Ar' +H2-* ArH* + H) or by efficient charge transfer reactions (Ar+ + H,O + H,O' + Ar) to produce a high number of reagent ions. Samples of different organic compounds were introduced through a sample inlet orifice and their chemical ionization spectra recorded with a quadrupole rn<ass spectrometer
Physics Letters A, 1981
ABSTRACT
Zeitschrift für Naturforschung A, 1971
Zeitschrift für angewandte Mathematik und Physik ZAMP, 1970
Zeitschrift für angewandte Mathematik und Physik ZAMP, 1978