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Evaluation of the 15-year ROM SAF monthly mean GPS radio occultation climate data record

Atmos.Meas.Tech. discussions - Thu, 06/11/2020 - 13:39
Evaluation of the 15-year ROM SAF monthly mean GPS radio occultation climate data record
Hans Gleisner, Kent B. Lauritsen, Johannes K. Nielsen, and Stig Syndergaard
Atmos. Meas. Tech., 13, 3081–3098, https://doi.org/10.5194/amt-13-3081-2020, 2020
Data from GPS radio occultation (RO) instruments aboard a series of satellites have been reprocessed by the ROM SAF. We describe the monthly mean RO climate data records (CDRs) and the methods for removing sampling errors. The quality of the CDRs is evaluated, with a focus on systematic differences between satellite missions. Between 8 and 30 km, the data quality and the inter-mission differences are small enough to allow the generation of combined multi-mission data records starting in 2001.

A hybrid method for reconstructing the historical evolution of aerosol optical depth from sunshine duration measurements

Atmos.Meas.Tech. discussions - Thu, 06/11/2020 - 13:39
A hybrid method for reconstructing the historical evolution of aerosol optical depth from sunshine duration measurements
William Wandji Nyamsi, Antti Lipponen, Arturo Sanchez-Lorenzo, Martin Wild, and Antti Arola
Atmos. Meas. Tech., 13, 3061–3079, https://doi.org/10.5194/amt-13-3061-2020, 2020
This paper proposes a novel and accurate method for estimating and reconstructing aerosol optical depth from sunshine duration measurements under cloud-free conditions at any place and time since the late 19th century. The method performs very well when compared to AErosol RObotic NETwork measurements and operates an efficient detection of signals from massive volcanic eruptions. Reconstructed long-term aerosol optical depths are in agreement with the dimming/brightening phenomenon.

A kernel-driven BRDF model to inform satellite-derived visible anvil cloud detection

Atmos.Meas.Tech. discussions - Thu, 06/11/2020 - 13:39
A kernel-driven BRDF model to inform satellite-derived visible anvil cloud detection
Benjamin Scarino, Kristopher Bedka, Rajendra Bhatt, Konstantin Khlopenkov, David R. Doelling, and William L. Smith Jr.
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-206,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper highlights a technique for facilitating anvil cloud detection based on visible observations that relies on comparative analysis with expected cloud reflectance for a given set of angles. A one-year database of anvil-identified pixels, as determined from IR observations, from several geostationary satellites was used to construct a bidirectional reflectance distribution function model to quantify typical anvil reflectance across almost all expected viewing, solar, and azimuth angles.

Interference from alkenes in chemiluminescent NOx measurements

Atmos.Meas.Tech. discussions - Thu, 06/11/2020 - 13:39
Interference from alkenes in chemiluminescent NO

Retrieved wind speed from the Orbiting Carbon Observatory-2

Atmos.Meas.Tech. discussions - Thu, 06/11/2020 - 13:39
Retrieved wind speed from the Orbiting Carbon Observatory-2
Robert R. Nelson, Annmarie Eldering, David Crisp, Aronne J. Merrelli, and Christopher W. O'Dell
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-180,2020
Preprint under review for AMT (discussion: open, 0 comments)
Measurements of surface wind speed over oceans are scientifically useful. Here we show that the Orbiting Carbon Observatory-2 (OCO-2), originally designed to measure carbon dioxide using reflected sunlight, can also accurately and precisely measure wind speed. OCO-2's high spatial resolution means that it can observe close to coastlines and therefore be used to study coastal wind processes and inform related economic sectors.

Evaluation of the 15-year ROM SAF monthly mean GPS radio occultation climate data record

Evaluation of the 15-year ROM SAF monthly mean GPS radio occultation climate data record
Hans Gleisner, Kent B. Lauritsen, Johannes K. Nielsen, and Stig Syndergaard
Atmos. Meas. Tech., 13, 3081–3098, https://doi.org/10.5194/amt-13-3081-2020, 2020
Data from GPS radio occultation (RO) instruments aboard a series of satellites have been reprocessed by the ROM SAF. We describe the monthly mean RO climate data records (CDRs) and the methods for removing sampling errors. The quality of the CDRs is evaluated, with a focus on systematic differences between satellite missions. Between 8 and 30 km, the data quality and the inter-mission differences are small enough to allow the generation of combined multi-mission data records starting in 2001.

A hybrid method for reconstructing the historical evolution of aerosol optical depth from sunshine duration measurements

A hybrid method for reconstructing the historical evolution of aerosol optical depth from sunshine duration measurements
William Wandji Nyamsi, Antti Lipponen, Arturo Sanchez-Lorenzo, Martin Wild, and Antti Arola
Atmos. Meas. Tech., 13, 3061–3079, https://doi.org/10.5194/amt-13-3061-2020, 2020
This paper proposes a novel and accurate method for estimating and reconstructing aerosol optical depth from sunshine duration measurements under cloud-free conditions at any place and time since the late 19th century. The method performs very well when compared to AErosol RObotic NETwork measurements and operates an efficient detection of signals from massive volcanic eruptions. Reconstructed long-term aerosol optical depths are in agreement with the dimming/brightening phenomenon.

A kernel-driven BRDF model to inform satellite-derived visible anvil cloud detection

A kernel-driven BRDF model to inform satellite-derived visible anvil cloud detection
Benjamin Scarino, Kristopher Bedka, Rajendra Bhatt, Konstantin Khlopenkov, David R. Doelling, and William L. Smith Jr.
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-206,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper highlights a technique for facilitating anvil cloud detection based on visible observations that relies on comparative analysis with expected cloud reflectance for a given set of angles. A one-year database of anvil-identified pixels, as determined from IR observations, from several geostationary satellites was used to construct a bidirectional reflectance distribution function model to quantify typical anvil reflectance across almost all expected viewing, solar, and azimuth angles.

Interference from alkenes in chemiluminescent NOx measurements

Interference from alkenes in chemiluminescent NO

Retrieved wind speed from the Orbiting Carbon Observatory-2

Retrieved wind speed from the Orbiting Carbon Observatory-2
Robert R. Nelson, Annmarie Eldering, David Crisp, Aronne J. Merrelli, and Christopher W. O'Dell
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-180,2020
Preprint under review for AMT (discussion: open, 0 comments)
Measurements of surface wind speed over oceans are scientifically useful. Here we show that the Orbiting Carbon Observatory-2 (OCO-2), originally designed to measure carbon dioxide using reflected sunlight, can also accurately and precisely measure wind speed. OCO-2's high spatial resolution means that it can observe close to coastlines and therefore be used to study coastal wind processes and inform related economic sectors.

A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER

Atmos.Meas.Tech. discussions - Wed, 06/10/2020 - 13:39
A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER
Yajun Zhu, Martin Kaufmann, Qiuyu Chen, Jiyao Xu, Qiucheng Gong, Jilin Liu, Daikang Wei, and Martin Riese
Atmos. Meas. Tech., 13, 3033–3042, https://doi.org/10.5194/amt-13-3033-2020, 2020
OH airglow emissions can be used to derive rotational temperature and trace constituents in the mesopause region, but systematic differences exist for the follow-up data using OH emission radiance as measured by SCIAMACHY and SABER. This paper makes a comparison of OH emission radiance as measured by them and shows the systematic differences between the two measurements. The radiometric calibration of the two instruments could potentially explain the differences between the two measurements.

A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data

Atmos.Meas.Tech. discussions - Wed, 06/10/2020 - 13:39
A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data
Swadhin Nanda, Martin de Graaf, J. Pepijn Veefkind, Maarten Sneep, Mark ter Linden, Jiyunting Sun, and Pieternel F. Levelt
Atmos. Meas. Tech., 13, 3043–3059, https://doi.org/10.5194/amt-13-3043-2020, 2020
This paper presents a first validation of the TROPOspheric Monitoring Instrument (TROPOMI) aerosol layer height (ALH) product, which is an estimate of the height of an aerosol layer using a spectrometer on board ESA's Sentinel-5 Precursor satellite mission. Comparison between the TROPOMI ALH product and co-located aerosol extinction heights from the CALIOP instrument on board NASA's CALIPSO mission show good agreement for selected cases over the ocean and large differences over land.

A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER

A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER
Yajun Zhu, Martin Kaufmann, Qiuyu Chen, Jiyao Xu, Qiucheng Gong, Jilin Liu, Daikang Wei, and Martin Riese
Atmos. Meas. Tech., 13, 3033–3042, https://doi.org/10.5194/amt-13-3033-2020, 2020
OH airglow emissions can be used to derive rotational temperature and trace constituents in the mesopause region, but systematic differences exist for the follow-up data using OH emission radiance as measured by SCIAMACHY and SABER. This paper makes a comparison of OH emission radiance as measured by them and shows the systematic differences between the two measurements. The radiometric calibration of the two instruments could potentially explain the differences between the two measurements.

A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data

A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data
Swadhin Nanda, Martin de Graaf, J. Pepijn Veefkind, Maarten Sneep, Mark ter Linden, Jiyunting Sun, and Pieternel F. Levelt
Atmos. Meas. Tech., 13, 3043–3059, https://doi.org/10.5194/amt-13-3043-2020, 2020
This paper presents a first validation of the TROPOspheric Monitoring Instrument (TROPOMI) aerosol layer height (ALH) product, which is an estimate of the height of an aerosol layer using a spectrometer on board ESA's Sentinel-5 Precursor satellite mission. Comparison between the TROPOMI ALH product and co-located aerosol extinction heights from the CALIOP instrument on board NASA's CALIPSO mission show good agreement for selected cases over the ocean and large differences over land.

Comparison of dimension reduction techniques in the analysis of mass spectrometry data

Atmos.Meas.Tech. discussions - Tue, 06/09/2020 - 13:39
Comparison of dimension reduction techniques in the analysis of mass spectrometry data
Sini Isokääntä, Eetu Kari, Angela Buchholz, Liqing Hao, Siegfried Schobesberger, Annele Virtanen, and Santtu Mikkonen
Atmos. Meas. Tech., 13, 2995–3022, https://doi.org/10.5194/amt-13-2995-2020, 2020
Online mass spectrometry produces large amounts of data. These data can be interpreted with statistical methods, enabling scientists to more easily understand the underlying processes. We compared these techniques on car exhaust measurements. We show differences and similarities between the methods and give recommendations on applicability of the methods on certain types of data. We show that applying multiple methods leads to more robust results, thus increasing reliability of the findings.

First observations of the McMurdo–South Pole oblique ionospheric HF channel

Atmos.Meas.Tech. discussions - Tue, 06/09/2020 - 13:39
First observations of the McMurdo–South Pole oblique ionospheric HF channel
Alex T. Chartier, Juha Vierinen, and Geonhwa Jee
Atmos. Meas. Tech., 13, 3023–3031, https://doi.org/10.5194/amt-13-3023-2020, 2020
A novel oblique ionospheric radio sounder has been developed and demonstrated in Antarctica. The transmitter was located at McMurdo and the receiver at the South Pole (1356 km great-circle path). The system cycled through 12 frequencies each minute and recorded signal time of flight, intensity, and Doppler. This allowed for the estimation of peak ionospheric electron density, which validated well against independent data from the nearby Jang Bogo ionosonde and GPS TEC.

Aqueous particle generation with a 3D printed nebulizer

Atmos.Meas.Tech. discussions - Tue, 06/09/2020 - 13:39
Aqueous particle generation with a 3D printed nebulizer
Michael Rösch and Daniel J. Cziczo
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-155,2020
Preprint under review for AMT (discussion: open, 0 comments)
The need for a simple atomizer with a high output stability combined with the capabilities of CAD software and high resolution 3D printing has allowed for the design, production and testing of the PRinted drOpleT Generator (PROTeGE) to generate liquid particles from solutions. The size and number concentrations of the generated particles has been characterized with different ammonium sulfate and PSL solutions. PROTeGE is easy to operate, requires minimal maintenance and is cost-effective.

Comparison of dimension reduction techniques in the analysis of mass spectrometry data

Comparison of dimension reduction techniques in the analysis of mass spectrometry data
Sini Isokääntä, Eetu Kari, Angela Buchholz, Liqing Hao, Siegfried Schobesberger, Annele Virtanen, and Santtu Mikkonen
Atmos. Meas. Tech., 13, 2995–3022, https://doi.org/10.5194/amt-13-2995-2020, 2020
Online mass spectrometry produces large amounts of data. These data can be interpreted with statistical methods, enabling scientists to more easily understand the underlying processes. We compared these techniques on car exhaust measurements. We show differences and similarities between the methods and give recommendations on applicability of the methods on certain types of data. We show that applying multiple methods leads to more robust results, thus increasing reliability of the findings.

First observations of the McMurdo–South Pole oblique ionospheric HF channel

First observations of the McMurdo–South Pole oblique ionospheric HF channel
Alex T. Chartier, Juha Vierinen, and Geonhwa Jee
Atmos. Meas. Tech., 13, 3023–3031, https://doi.org/10.5194/amt-13-3023-2020, 2020
A novel oblique ionospheric radio sounder has been developed and demonstrated in Antarctica. The transmitter was located at McMurdo and the receiver at the South Pole (1356 km great-circle path). The system cycled through 12 frequencies each minute and recorded signal time of flight, intensity, and Doppler. This allowed for the estimation of peak ionospheric electron density, which validated well against independent data from the nearby Jang Bogo ionosonde and GPS TEC.

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