GOMOS bright limb ozone data set

Abstract. We have created a daytime ozone profile data set from the measurements of the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on board the Envisat satellite. This so-called GOMOS bright limb (GBL) data set contains ~ 358 000 stratospheric daytime ozone profiles measured by GOMOS in 2002–2012. The GBL data set complements the widely used GOMOS night-time data based on stellar occultation measurements. The GBL data set is based on the GOMOS daytime occultations but instead of the transmitted star light, we use limb scattered solar light. The ozone profiles retrieved from these radiance spectra cover 18–60 km tangent height range and have approximately 2–3 km vertical resolution. We show that these profiles are generally in better than 10% agreement with the NDACC (Network for the Detection of Atmospheric Composition Change) ozone sounding profiles and with the GOMOS night-time, MLS (Microwave Limb Sounder), and OSIRIS (Optical Spectrograph, and InfraRed Imaging System) satellite measurements. However, there is a 10–13% negative bias at 40 km tangent height and a 10–50% positive bias at 50 km when the solar zenith angle > 75°. These biases are most likely caused by stray light which is difficult to characterize and remove entirely from the measured spectra. Nevertheless, the GBL data set approximately doubles the amount of useful GOMOS ozone profiles and improves coverage of the summer pole.

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GOMOS bright limb ozone data set

Atmospheric Measurement Techniques ◽

10.5194/amt-8-3107-2015 ◽

2015 ◽

Vol 8 (8) ◽

pp. 3107-3115 ◽

Cited By ~ 3

Author(s):

S. Tukiainen ◽

E. Kyrölä ◽

J. Tamminen ◽

J. Kujanpää ◽

L. Blanot

Keyword(s):

Stray Light ◽

Atmospheric Composition ◽

Profile Data ◽

Satellite Measurements ◽

Data Set ◽

Infrared Imager ◽

Ozone Profile ◽

Stellar Occultation ◽

Ozone Monitoring ◽

Better Than

Abstract. We have created a daytime ozone profile data set from the measurements of the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on board the Envisat satellite. This so-called GOMOS bright limb (GBL) data set contains ∼ 358 000 stratospheric daytime ozone profiles measured by GOMOS in 2002–2012. The GBL data set complements the widely used GOMOS nighttime data based on stellar occultation measurements. The GBL data set is based on the GOMOS daytime occultations but instead of the transmitted star light we use limb-scattered solar light. The ozone profiles retrieved from these radiance spectra cover the 18–60 km altitude range and have approximately 2–3 km vertical resolution. We show that these profiles are generally in better than 10 % agreement with the NDACC (Network for the Detection of Atmospheric Composition Change) ozonesonde profiles and with the GOMOS nighttime, MLS (Microwave Limb Sounder), and OSIRIS (Optical Spectrograph and InfraRed Imager System) satellite measurements. However, there is a 10–13 % negative bias at 40 km altitude and a 10–50 % positive bias at 50 km for solar zenith angles > 75°. These biases are most likely caused by stray light which is difficult to characterize and to remove entirely from the measured spectra. Nevertheless, the GBL data set approximately doubles the amount of useful GOMOS ozone profiles and improves coverage of the summer pole.

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Retrieval of ozone profiles from GOMOS limb scattered measurements

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-3-4355-2010 ◽

2010 ◽

Vol 3 (5) ◽

pp. 4355-4382 ◽

Cited By ~ 1

Author(s):

S. Tukiainen ◽

E. Kyrölä ◽

P. T. Verronen ◽

D. Fussen ◽

L. Blanot ◽

...

Keyword(s):

Imaging System ◽

Signal To Noise Ratio ◽

Stratospheric Ozone ◽

Stray Light ◽

Time Data ◽

Night Time ◽

Retrieval Method ◽

Stellar Occultation ◽

Infra Red ◽

Better Than

Abstract. The GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite measures the vertical composition of the atmosphere using the stellar occultation technique. While the night-time data of GOMOS are proved to be of good quality, the daytime observations are more challenging due to poorer signal-to-noise ratio. In this paper we present an alternative technique, which uses GOMOS limb scattered radiances instead of the stellar signal, to retrieve stratospheric ozone profiles. Like for many other limb-viewing instruments, GOMOS observations contain stray light at high altitudes. We introduce a method for removing the stray light and demonstrate its feasibility by comparing the corrected radiances against those from the OSIRIS (Optical Spectrograph & Infra Red Imaging System) instrument. For the retrieval of ozone profiles, an onion peeling method is used. The first validation results suggest that the retrieval of stratospheric ozone is possible with a typical accuracy better than 10% at 22–50 km. GOMOS has measured about 350 000 daytime profiles since 2002. The new retrieval method presented here makes this large amount of data finally available for scientific use.

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Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2

Atmospheric Measurement Techniques ◽

10.5194/amt-8-2093-2015 ◽

2015 ◽

Vol 8 (5) ◽

pp. 2093-2120 ◽

Cited By ~ 13

Author(s):

A. Keppens ◽

J.-C. Lambert ◽

J. Granville ◽

G. Miles ◽

R. Siddans ◽

...

Keyword(s):

Information Content ◽

Global Climate ◽

Optimal Estimation ◽

Round Robin ◽

Atmospheric Composition ◽

Data Sets ◽

Profile Data ◽

Satellite Measurements ◽

Data Set ◽

Ozone Profile

Abstract. A methodology for the round-robin evaluation and the geophysical validation of ozone profile data retrieved from nadir UV backscatter satellite measurements is detailed and discussed, consisting of data set content studies, information content studies, co-location studies, and comparisons with reference measurements. Within the European Space Agency's Climate Change Initiative on ozone (Ozone_cci project), the proposed round-robin procedure is applied to two nadir ozone profile data sets retrieved at the Royal Netherlands Meteorological Institute (KNMI) and the Rutherford Appleton Laboratory (RAL, United Kingdom), using their respective OPERA v1.26 and RAL v2.1 optimal estimation algorithms, from MetOp-A GOME-2 (i.e. the second generation Global Ozone Monitoring Experiment on the first Meteorological Operational Satellite) measurements taken in 2008. The ground-based comparisons use ozonesonde and lidar profiles as reference data, acquired by the Network for the Detection of Atmospheric Composition Change (NDACC), Southern Hemisphere Additional Ozonesonde programme (SHADOZ), and other stations of the World Meteorological Organisation's Global Atmosphere Watch (WMO GAW). This direct illustration highlights practical issues that inevitably emerge from discrepancies in e.g. profile representation and vertical smoothing, for which different recipes are investigated and discussed. Several approaches for information content quantification, vertical resolution estimation, and reference profile resampling are compared and applied as well. The paper concludes with compliance estimates of the two GOME-2 ozone profile data sets with user requirements from the Global Climate Observing System (GCOS) and from climate modellers.

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Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-11481-2014 ◽

2014 ◽

Vol 7 (11) ◽

pp. 11481-11546 ◽

Cited By ~ 4

Author(s):

A. Keppens ◽

J.-C. Lambert ◽

J. Granville ◽

G. Miles ◽

R. Siddans ◽

...

Keyword(s):

Information Content ◽

Optimal Estimation ◽

Round Robin ◽

Atmospheric Composition ◽

User Requirements ◽

Satellite Measurements ◽

Estimation Algorithms ◽

Ozone Profile ◽

Reference Measurements ◽

Resolution Estimation

Abstract. A methodology for the round-robin evaluation and geophysical validation of ozone profile data retrieved from nadir UV backscatter satellite measurements is detailed and discussed, consisting of dataset content studies, information content studies, co-location studies, and comparisons with reference measurements. Within ESA's Climate Change Initiative on ozone (Ozone_cci project), the proposed round-robin procedure is applied to two nadir ozone profile datasets retrieved at KNMI and RAL, using their respective OPERA v1.26 and RAL v2.1 optimal estimation algorithms, from MetOp-A GOME-2 measurements taken in 2008. The ground-based comparisons use ozonesonde and lidar profiles as reference data, acquired by the Network for the Detection of Atmospheric Composition Change (NDACC), Southern Hemisphere Additional Ozonesonde programme (SHADOZ), and other stations of WMO's Global Atmosphere Watch. This direct illustration highlights practical issues that inevitably emerge from discrepancies in e.g. profile representation and vertical smoothing, for which different recipes are investigated and discussed. Several approaches for information content quantification, vertical resolution estimation, and reference profile resampling are compared and applied as well. The paper concludes with compliance estimates of the two GOME-2 ozone profile datasets with user requirements from GCOS and from climate modellers.

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Validation of ozone profile retrievals derived from the OMPS LP version 2.5 algorithm against correlative satellite measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-11-2837-2018 ◽

2018 ◽

Vol 11 (5) ◽

pp. 2837-2861 ◽

Cited By ~ 9

Author(s):

Natalya A. Kramarova ◽

Pawan K. Bhartia ◽

Glen Jaross ◽

Leslie Moy ◽

Philippe Xu ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Infrared Imaging ◽

Imaging System ◽

Thermal Sensitivity ◽

Retrieval Algorithm ◽

Ozone Profile ◽

Mean Differences ◽

The Stability ◽

Cloud Tops ◽

Spectral Ranges

Abstract. The Limb Profiler (LP) is a part of the Ozone Mapping and Profiler Suite launched on board of the Suomi NPP satellite in October 2011. The LP measures solar radiation scattered from the atmospheric limb in ultraviolet and visible spectral ranges between the surface and 80 km. These measurements of scattered solar radiances allow for the retrieval of ozone profiles from cloud tops up to 55 km. The LP started operational observations in April 2012. In this study we evaluate more than 5.5 years of ozone profile measurements from the OMPS LP processed with the new NASA GSFC version 2.5 retrieval algorithm. We provide a brief description of the key changes that had been implemented in this new algorithm, including a pointing correction, new cloud height detection, explicit aerosol correction and a reduction of the number of wavelengths used in the retrievals. The OMPS LP ozone retrievals have been compared with independent satellite profile measurements obtained from the Aura Microwave Limb Sounder (MLS), Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) and Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). We document observed biases and seasonal differences and evaluate the stability of the version 2.5 ozone record over 5.5 years. Our analysis indicates that the mean differences between LP and correlative measurements are well within required ±10 % between 18 and 42 km. In the upper stratosphere and lower mesosphere (> 43 km) LP tends to have a negative bias. We find larger biases in the lower stratosphere and upper troposphere, but LP ozone retrievals have significantly improved in version 2.5 compared to version 2 due to the implemented aerosol correction. In the northern high latitudes we observe larger biases between 20 and 32 km due to the remaining thermal sensitivity issue. Our analysis shows that LP ozone retrievals agree well with the correlative satellite observations in characterizing vertical, spatial and temporal ozone distribution associated with natural processes, like the seasonal cycle and quasi-biennial oscillations. We found a small positive drift ∼ 0.5 % yr−1 in the LP ozone record against MLS and OSIRIS that is more pronounced at altitudes above 35 km. This pattern in the relative drift is consistent with a possible 100 m drift in the LP sensor pointing detected by one of our altitude-resolving methods.

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Regional Poverty and Inequality in the Xiamen-Zhangzhou-Quanzhou City Cluster in China Based on NPP/VIIRS Night-Time Light Imagery

Sustainability ◽

10.3390/su12062547 ◽

2020 ◽

Vol 12 (6) ◽

pp. 2547 ◽

Cited By ~ 3

Author(s):

Wenbin Pan ◽

Hongming Fu ◽

Peng Zheng

Keyword(s):

Infrared Imaging ◽

Spatial Scales ◽

Principal Component ◽

Regional Inequality ◽

Theil Index ◽

Poverty Index ◽

Time Data ◽

Night Time ◽

Poverty And Inequality ◽

City Cluster

Poverty and inequality remain outstanding challenges in many global regions. Understanding the underlying social and economic conditions is important in formulating poverty eradication strategies. Using Visible Infrared Imaging Radiometer Suite (VIIRS) Night-Time Light (NTL) images and multidimensional socioeconomic data between 2012 and 2018, this study measured regional poverty and inequality in the Xiamen-Zhangzhou-Quanzhou city cluster in the People’s Republic of China. Principal Component Analysis (PCA) and the Theil index decomposition method were used to establish an Integrated Poverty Index (IPI) and a regional inequality index, respectively. The results indicated that: (1) The poverty index is affected by the geographical location, policies, and resources of a district/county. A significant logarithmic correlation model between VIIRS Average Light Index (ALI) and IPI was established. (2) The Theil index derived from Gross Domestic Product (GDP) indicators showed that overall inequality and between-prefecture inequality declined, while within-prefecture inequality remained unchanged. In terms of the contributions to regional inequality, the contribution of within-prefecture inequality is the largest. The results indicated that Suomi National Polar Partnership/Visible Infrared Imaging Radiometer Suite (NPP/VIIRS) night-time data can help to perform district/county-level poverty assessments at small and medium spatial scales, although the evaluation effect on regional inequality is slightly lower.

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Variability and evolution of the midlatitude stratospheric aerosol budget from 22 years of ground-based lidar and satellite observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-1829-2017 ◽

2017 ◽

Vol 17 (3) ◽

pp. 1829-1845 ◽

Cited By ~ 24

Author(s):

Sergey M. Khaykin ◽

Sophie Godin-Beekmann ◽

Philippe Keckhut ◽

Alain Hauchecorne ◽

Julien Jumelet ◽

...

Keyword(s):

Asian Monsoon ◽

Infrared Imaging ◽

Imaging System ◽

Late Summer ◽

Stratospheric Aerosol ◽

Atmospheric Composition ◽

Orthogonal Polarization ◽

Asian Monsoon Region ◽

Lidar Measurements ◽

Ground Based Lidar

Abstract. The article presents new high-quality continuous stratospheric aerosol observations spanning 1994–2015 at the French Observatoire de Haute-Provence (OHP, 44° N, 6° E) obtained by two independent, regularly maintained lidar systems operating within the Network for Detection of Atmospheric Composition Change (NDACC). Lidar series are compared with global-coverage observations by Stratospheric Aerosol and Gas Experiment (SAGE II), Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and Ozone Mapping Profiling Suite (OMPS) satellite instruments, altogether covering the time span of OHP lidar measurements. Local OHP and zonal-mean satellite series of stratospheric aerosol optical depth are in excellent agreement, allowing for accurate characterization of stratospheric aerosol evolution and variability at northern midlatitudes during the last 2 decades. The combination of local and global observations is used for a careful separation between volcanically perturbed and quiescent periods. While the volcanic signatures dominate the stratospheric aerosol record, the background aerosol abundance is found to be modulated remotely by the poleward transport of convectively cleansed air from the deep tropics and aerosol-laden air from the Asian monsoon region. The annual cycle of background aerosol at midlatitudes, featuring a minimum during late spring and a maximum during late summer, correlates with that of water vapor from the Aura Microwave Limb Sounder (MLS). Observations covering two volcanically quiescent periods over the last 2 decades provide an indication of a growth in the nonvolcanic component of stratospheric aerosol. A statistically significant factor of 2 increase in nonvolcanic aerosol since 1998, seasonally restricted to late summer and fall, is associated with the influence of the Asian monsoon and growing pollution therein.

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Retrieval of ozone profiles from GOMOS limb scattered measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-4-659-2011 ◽

2011 ◽

Vol 4 (4) ◽

pp. 659-667 ◽

Cited By ~ 10

Author(s):

S. Tukiainen ◽

E. Kyrölä ◽

P. T. Verronen ◽

D. Fussen ◽

L. Blanot ◽

...

Keyword(s):

Imaging System ◽

Signal To Noise Ratio ◽

Stray Light ◽

Data Sets ◽

Night Time ◽

Retrieval Method ◽

Stellar Radiation ◽

Stellar Occultation ◽

Infra Red ◽

Ozone Monitoring

Abstract. The GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite measures the vertical composition of the atmosphere using the stellar occultation technique. While the night-time occultations of GOMOS have been proven to be of good quality, the daytime occultations are more challenging due to weaker signal-to-noise ratio. During daytime GOMOS measures limb scattered solar radiation in addition to stellar radiation. In this paper we introduce a retrieval method that determines ozone profiles between 20–60 km from GOMOS limb scattered solar radiances. GOMOS observations contain a considerable amount of stray light at high altitudes. We introduce a method for removing stray light and demonstrate its feasibility by comparing the corrected radiances against those measured by the OSIRIS (Optical Spectrograph & Infra Red Imaging System) instrument. For the retrieval of ozone profiles, a standard onion peeling method is used. The first comparisons with other data sets suggest that the retrieved ozone profiles in 22–50 km are within 10% compared with the GOMOS night-time occultations and within 15% compared with OSIRIS. GOMOS has measured about 350 000 daytime profiles since 2002. The retrieval method presented here makes this large amount of data available for scientific use.

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Relative drifts and biases between six ozone limb satellite measurements from the last decade

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-3697-2015 ◽

2015 ◽

Vol 8 (4) ◽

pp. 3697-3728 ◽

Cited By ~ 2

Author(s):

N. Rahpoe ◽

M. Weber ◽

A. V. Rozanov ◽

K. Weigel ◽

H. Bovensmann ◽

...

Keyword(s):

Relative Difference ◽

Third Party ◽

Satellite Measurements ◽

Data Set ◽

Middle Latitudes ◽

Ozone Profile ◽

Combining Data ◽

High Vertical Resolution ◽

Long Term Trend

Abstract. As part of ESA's climate change initiative high vertical resolution ozone profiles from three instruments all aboard ESA's Envisat (GOMOS, MIPAS, SCIAMACHY) in combination with ESA's third party missions (OSIRIS, SMR, ACE-FTS) are to be combined in order to create an essential climate variable data record for the last decade. A prerequisite before combining data is the examination of differences and drifts between the datasets. In this paper, we present a detailed analysis of ozone profile differences based on pairwise collocated measuerements, including the evolution of the differences with time. Such a diagnosis is helpful to identify strengths and weaknesses of each data set that may vary in time and introduce uncertainties in long-term trend estimates. Main results of this paper indicate that the 6 instruments perform well in the stratosphere particularly between 20 and 40 km with a mean relative difference of ±5% (middle latitudes) to ±10% (tropics). Larger differences and variability in the differences are found in the upper troposphere lower stratosphere region and in the mesosphere. The analysis reveals that the relative drift between the sensors is not statistically significant for most pairs of instruments.

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