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Article ; Online: Simultaneous assimilation of ozone profiles from multiple UV-VIS satellite instruments

J. C. A. van Peet / R. J. van der A / H. M. Kelder / P. F. Levelt

Atmospheric Chemistry and Physics, Vol 18, Pp 1685-

2018 Volume 1704

Abstract: A three-dimensional global ozone distribution has been derived from assimilation of ozone profiles that were observed by satellites. By simultaneous assimilation of ozone profiles retrieved from the nadir looking satellite instruments Global Ozone ... ...

Abstract	A three-dimensional global ozone distribution has been derived from assimilation of ozone profiles that were observed by satellites. By simultaneous assimilation of ozone profiles retrieved from the nadir looking satellite instruments Global Ozone Monitoring Experiment 2 (GOME-2) and Ozone Monitoring Instrument (OMI), which measure the atmosphere at different times of the day, the quality of the derived atmospheric ozone field has been improved. The assimilation is using an extended Kalman filter in which chemical transport model TM5 has been used for the forecast. The combined assimilation of both GOME-2 and OMI improves upon the assimilation results of a single sensor. The new assimilation system has been demonstrated by processing 4 years of data from 2008 to 2011. Validation of the assimilation output by comparison with sondes shows that biases vary between −5 and +10 % between the surface and 100 hPa. The biases for the combined assimilation vary between −3 and +3 % in the region between 100 and 10 hPa where GOME-2 and OMI are most sensitive. This is a strong improvement compared to direct retrievals of ozone profiles from satellite observations.
Keywords	Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	290
Language	English
Publishing date	2018-02-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Interannual variability of the stratospheric wave driving during northern winter

A. J. Haklander / P. C. Siegmund / H. M. Kelder

Atmospheric Chemistry and Physics Discussions, Vol 7, Iss 1, Pp 65-

2007 Volume 91

Abstract: The strength of the stratospheric wave driving during northern winter is often quantified by the January–February mean poleward eddy heat flux at 100 hPa, averaged over 40°–80° N (or a similar area and period). Despite the dynamical and chemical ... ...

Abstract	The strength of the stratospheric wave driving during northern winter is often quantified by the January–February mean poleward eddy heat flux at 100 hPa, averaged over 40°–80° N (or a similar area and period). Despite the dynamical and chemical relevance of the wave driving, the causes for its variability are still not well understood. In this study, 45 years of ERA-40 reanalysis data are used to examine several factors that significantly affect the interannual variability of the wave driving. The total poleward heat flux at 100 hPa is poorly correlated with that in the troposphere, suggesting a decoupling between 100 hPa and the troposphere. However, the individual zonal wave-1 and wave-2 contributions to the wave driving at 100 hPa do exhibit a significant coupling with the troposphere, predominantly due to their stationary components. The stationary wave-1 contribution to the total wave driving significantly depends on the latitude of the stationary wave-1 source in the troposphere. The results suggest that this dependence is associated with the varying ability of stationary wave-1 activity to enter the tropospheric waveguide at mid- to subpolar latitudes. If composites of strong and weak wave-driving years are compared, we find significantly higher refractive index values in the midlatitude stratosphere for the strong composite than for the weak composite. Since wave activity tends to propagate towards higher refractive index values, this could explain part of the interannual variability of the wave driving. Finally, an alternative approach is taken, in which the wave driving anomalies are separated into three parts: one part due to anomalies in the zonal correlation between the eddy temperature and eddy meridional wind, another part due to anomalies in the zonal eddy temperature amplitude, and a third part due to anomalies in the zonal eddy meridional wind amplitude. It is found that year-to-year variability in the zonal correlation between the eddy temperature and the eddy meridional wind is the most dominant factor in explaining the year-to-year variability of the poleward eddy heat flux.
Keywords	Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Geophysics. Cosmic physics ; QC801-809
Subject code	551
Language	English
Publishing date	2007-01-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Interannual variability of the stratospheric wave driving during northern winter

H. M. Kelder / P. C. Siegmund / A. J. Haklander

Atmospheric Chemistry and Physics, Vol 7, Iss 10, Pp 2575-

2007 Volume 2584

Abstract	The strength of the stratospheric wave driving during northern winter is often quantified by the January–February mean poleward eddy heat flux at 100 hPa, averaged over 40°–80° N (or a similar area and period). Despite the dynamical and chemical relevance of the wave driving, the causes for its variability are still not well understood. In this study, ERA-40 reanalysis data for the period 1979–2002 are used to examine several factors that significantly affect the interannual variability of the wave driving. The total poleward heat flux at 100 hPa is poorly correlated with that in the troposphere, suggesting a decoupling between 100 hPa and the troposphere. However, the individual zonal wave-1 and wave-2 contributions to the wave driving at 100 hPa do exhibit a significant coupling with the troposphere, predominantly their stationary components. The stationary wave-1 contribution to the total wave driving significantly depends on the latitude of the stationary wave-1 source in the troposphere. The results suggest that this dependence is associated with the varying ability of stationary wave-1 activity to enter the tropospheric waveguide at mid-latitudes. The wave driving anomalies are separated into three parts: one part due to anomalies in the zonal correlation coefficient between the eddy temperature and eddy meridional wind, another part due to anomalies in the zonal eddy temperature amplitude, and a third part due to anomalies in the zonal eddy meridional wind amplitude. It is found that year-to-year variability in the zonal correlation coefficient between the eddy temperature and the eddy meridional wind is the most dominant factor in explaining the year-to-year variability of the poleward eddy heat flux.
Keywords	Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	551
Language	English
Publishing date	2007-05-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Analysis of the frequency-dependent response to wave forcing in the extratropics

A. J. Haklander / P. C. Siegmund / H. M. Kelder

Atmospheric Chemistry and Physics Discussions, Vol 6, Iss 1, Pp 1399-

2006 Volume 1411

Abstract: A quasigeostrophic model for the frequency-dependent response of the zonal-mean flow to planetary-wave forcing at Northern Hemisphere (NH) midlatitudes is applied to 4-D-Var ECMWF analysis data for six extended winter seasons. The theoretical response is ...

Abstract	A quasigeostrophic model for the frequency-dependent response of the zonal-mean flow to planetary-wave forcing at Northern Hemisphere (NH) midlatitudes is applied to 4-D-Var ECMWF analysis data for six extended winter seasons. The theoretical response is a non-linear function of the frequency of the forcing, the thermal damping time α −1 , and a scaling parameter μ which includes the aspect ratio of the meridional to the vertical length scale of the response. Non-linear regression of the calculated response from the analyses onto the theoretical response yields height-dependent estimates for both α −1 and μ. The thermal damping time estimated from this dynamical model is about 2 days in the troposphere, 7–10 days in the stratosphere, and 2–4 days in the lower mesosphere. These estimates generally lie within the range of existing estimates, although the values we find for the troposphere are significantly smaller than those calculated in several radiative transfer modeling studies. At most levels, the estimates for μ are significantly lower than can be derived from scaling arguments that apply outside the forcing region. We illustrate with an example how the response of the meridional circulation inside the forcing area can have a higher aspect ratio than the effective response outside the forcing area.
Keywords	Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Geophysics. Cosmic physics ; QC801-809
Subject code	333
Language	English
Publishing date	2006-02-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Analysis of the frequency-dependent response to wave forcing in the extratropics

A. J. Haklander / P. C. Siegmund / H. M. Kelder

Atmospheric Chemistry and Physics, Vol 6, Iss 12, Pp 4477-

2006 Volume 4481

Abstract	A quasigeostrophic model for the frequency-dependent response of the zonal-mean flow to planetary-wave forcing at Northern Hemisphere (NH) midlatitudes is applied to 4-D-Var ECMWF analysis data for six extended winter seasons. The theoretical response is a non-linear function of the frequency of the forcing, the thermal damping time α −1 , and a scaling parameter µ which includes the aspect ratio of the meridional to the vertical length scale of the response. Regression of the calculated response from the analyses onto the theoretical response yields height-dependent estimates for both α −1 and µ. The thermal damping time estimated from this dynamical model is about 2 days in the troposphere, 7–10 days in the stratosphere, and 2–4 days in the lower mesosphere. For the stratosphere and lower mesosphere, the estimates lie within the range of existing radiative damping time estimates, but for the troposphere they are significantly smaller.
Keywords	Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	333
Language	English
Publishing date	2006-01-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Ozone ProfilE Retrieval Algorithm (OPERA) for nadir-looking satellite instruments in the UV–VIS

J. C. A. van Peet / R. J. van der A / O. N. E. Tuinder / E. Wolfram / J. Salvador / P. F. Levelt / H. M. Kelder

Atmospheric Measurement Techniques, Vol 7, Iss 3, Pp 859-

2014 Volume 876

Abstract: For the retrieval of the vertical distribution of ozone in the atmosphere the Ozone ProfilE Retrieval Algorithm (OPERA) has been further developed. The new version (1.26) of OPERA is capable of retrieving ozone profiles from UV–VIS observations of most ... ...

Abstract	For the retrieval of the vertical distribution of ozone in the atmosphere the Ozone ProfilE Retrieval Algorithm (OPERA) has been further developed. The new version (1.26) of OPERA is capable of retrieving ozone profiles from UV–VIS observations of most nadir-looking satellite instruments like GOME, SCIAMACHY, OMI and GOME-2. The setup of OPERA is described and results are presented for GOME and GOME-2 observations. The retrieved ozone profiles are globally compared to ozone sondes for the years 1997 and 2008. Relative differences between GOME/GOME-2 and ozone sondes are within the limits as specified by the user requirements from the Climate Change Initiative (CCI) programme of ESA (20% in the troposphere, 15% in the stratosphere). To demonstrate the performance of the algorithm under extreme circumstances, the 2009 Antarctic ozone hole season was investigated in more detail using GOME-2 ozone profiles and lidar data, which showed an unusual persistence of the vortex over the Río Gallegos observing station (51° S, 69.3° W). By applying OPERA to multiple instruments, a time series of ozone profiles from 1996 to 2013 from a single robust algorithm can be created.
Keywords	Meteorology. Climatology ; QC851-999 ; Physics ; QC1-999 ; Science ; Q
Subject code	290
Publishing date	2014-03-01T00:00:00Z
Publisher	Copernicus GmbH
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Ozone ProfilE Retrieval Algorithm for nadir-looking satellite instruments in the UV-VIS

J. C. A. van Peet / R. J. van der A / O. N. E. Tuinder / E. Wolfram / J. Salvador / P. F. Levelt / H. M. Kelder

Atmospheric Measurement Techniques Discussions, Vol 6, Iss 5, Pp 9061-

2013 Volume 9107

Abstract	For the retrieval of the vertical distribution of ozone in the atmosphere the Ozone ProfilE Retrieval Algorithm (OPERA) has been further developed. The new version (1.26) of OPERA is capable of retrieving ozone profiles from UV-VIS observations of most nadir looking satellite instruments like GOME, SCIAMACHY, OMI and GOME-2. The set-up of OPERA is described and results are presented for GOME and GOME-2 observations. The retrieved ozone profiles are globally compared to ozone sondes for the year 1997 and 2008. Relative differences between GOME/GOME-2 and ozone sondes are within the limits as specified by the user requirements from the Climate Change Initiative (CCI) program of ESA. To demonstrate the performance of the algorithm under extreme circumstances the 2009 Antarctic ozone hole season was investigated in more detail using GOME-2 ozone profiles and lidar data, which showed an unusual persistence of the vortex over the Río Gallegos observing station (51° S, 69.3° W). By applying OPERA to multiple instruments a timeseries of ozone profiles from 1996 to 2013 from a single robust algorithm can be created.
Keywords	Meteorology. Climatology ; QC851-999 ; Physics ; QC1-999 ; Science ; Q ; DOAJ:Meteorology and Climatology ; DOAJ:Earth and Environmental Sciences
Subject code	290
Language	English
Publishing date	2013-10-01T00:00:00Z
Publisher	Copernicus GmbH
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Estimates of lightning NO x production from GOME satellite observations

H. M. Kelder / E. W. Meijer / H. J. Eskes / K. F. Boersma

Atmospheric Chemistry and Physics Discussions, Vol 5, Iss 3, Pp 3047-

2005 Volume 3104

Abstract: Tropospheric NO 2 column retrievals from the Global Ozone Monitoring Experiment (GOME) satellite spectrometer are used to quantify the source strength and 3D distribution of lightning produced nitrogen oxides (NO x =NO 2 +NO 2 ). A sharp increase of NO 2 ...

Abstract	Tropospheric NO 2 column retrievals from the Global Ozone Monitoring Experiment (GOME) satellite spectrometer are used to quantify the source strength and 3D distribution of lightning produced nitrogen oxides (NO x =NO 2 +NO 2 ). A sharp increase of NO 2 is observed at convective cloud tops with increasing cloud top height, consistent with a power-law behaviour with power 5±2. Convective production of clouds with the same cloud height are found to produce NO 2 with a ratio 1.6/1 for continents compared to oceans. This relation between cloud properties and NO 2 is used to construct a 10:30 local time global lightning NO 2 production map for 1997. An extensive statistical comparison is conducted to investigate the capability of the TM3 chemistry transport model to reproduce observed patterns of lightning NO 2 in time and space. This comparison uses the averaging kernel to relate modelled profiles of NO 2 to observed NO 2 columns. It exploits a masking scheme to minimise the interference of other NO x sources on the observed total columns. Simulations are performed with two lightning parametrisations, one relating convective preciptation (CP scheme) to lightning flash distributions, and the other relating the fifth power of the cloud top height (H5 scheme) to lightning distributions. The satellite-retrieved NO 2 fields show significant correlations with the simulated lightning contribution to the NO 2 concentrations for both parametrisations. Over tropical continents modelled lightning NO 2 shows remarkable quantitative agreement with observations. Over the oceans however, the two model lightning parametrisations overestimate the retrieved NO 2 attributed to lightning. Possible explanations for these overestimations are discussed. The ratio between satellite-retrieved NO 2 and modelled lightning NO 2 is used to rescale the original modelled lightning NO x production. Eight estimates of the lightning NO x production in 1997 are obtained from spatial and temporal correlation methods, from cloud-free and cloud-covered observations, and from two different lightning parametrisations. Accounting for a wide variety of random and possible systematic errors, we estimate the global NO x production from lightning to be in the range 1.1–6.4 TgN in 1997.
Keywords	Environmental sciences ; GE1-350 ; Geography. Anthropology. Recreation ; G ; DOAJ:Environmental Sciences ; DOAJ:Earth and Environmental Sciences ; Geophysics. Cosmic physics ; QC801-809
Subject code	290
Language	English
Publishing date	2005-05-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Estimates of lightning NO x production from GOME satellite observations

K. F. Boersma / H. J. Eskes / E. W. Meijer / H. M. Kelder

Atmospheric Chemistry and Physics, Vol 5, Iss 9, Pp 2311-

2005 Volume 2331

Abstract: Tropospheric NO 2 column retrievals from the Global Ozone Monitoring Experiment (GOME) satellite spectrometer are used to quantify the source strength and 3-D distribution of lightning produced nitrogen oxides (NO x =NO+NO 2 ). A sharp increase of NO 2 ... ...

Abstract	Tropospheric NO 2 column retrievals from the Global Ozone Monitoring Experiment (GOME) satellite spectrometer are used to quantify the source strength and 3-D distribution of lightning produced nitrogen oxides (NO x =NO+NO 2 ). A sharp increase of NO 2 is observed at convective cloud tops with increasing cloud top height, consistent with a power-law behaviour with power 5±2. Convective production of clouds with the same cloud height are found to produce NO 2 with a ratio 1.6/1 for continents compared to oceans. This relation between cloud properties and NO 2 is used to construct a 10:30 local time global lightning NO 2 production map for 1997. An extensive statistical comparison is conducted to investigate the capability of the TM3 chemistry transport model to reproduce observed patterns of lightning NO 2 in time and space. This comparison uses the averaging kernel to relate modelled profiles of NO 2 to observed NO 2 columns. It exploits a masking scheme to minimise the interference of other NO x sources on the observed total columns. Simulations are performed with two lightning parameterizations, one relating convective preciptation (CP scheme) to lightning flash distributions, and the other relating the fifth power of the cloud top height (H5 scheme) to lightning distributions. The satellite-retrieved NO 2 fields show significant correlations with the simulated lightning contribution to the NO 2 concentrations for both parameterizations. Over tropical continents modelled lightning NO 2 shows remarkable quantitative agreement with observations. Over the oceans however, the two model lightning parameterizations overestimate the retrieved NO 2 attributed to lightning. Possible explanations for these overestimations are discussed. The ratio between satellite-retrieved NO 2 and modelled lightning NO 2 is used to rescale the original modelled lightning NO x production. Eight estimates of the lightning NO x production in 1997 are obtained from spatial and temporal correlation methods, from cloud-free and cloud-covered observations, and from two different lightning parameterizations. Accounting for a wide variety of random and possible systematic errors, we estimate the global NO x production from lightning to be in the range 1.1–6.4 Tg N in 1997.
Keywords	Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	290
Language	English
Publishing date	2005-01-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The impact of MM5 and WRF meteorology over complex terrain on CHIMERE model calculations

A. de Meij / A. Gzella / C. Cuvelier / P. Thunis / B. Bessagnet / J. F. Vinuesa / L. Menut / H. M. Kelder

Atmospheric Chemistry and Physics, Vol 9, Iss 17, Pp 6611-

2009 Volume 6632

Abstract: The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the ...

Abstract	The objective of this study is to evaluate the impact of meteorological input data on calculated gas and aerosol concentrations. We use two different meteorological models (MM5 and WRF) together with the chemistry transport model CHIMERE. We focus on the Po valley area (Italy) for January and June 2005. Firstly we evaluate the meteorological parameters with observations. The analysis shows that the performance of both models in calculating surface parameters is similar, however differences are still observed. Secondly, we analyze the impact of using MM5 and WRF on calculated PM 10 and O 3 concentrations. In general CHIMERE/MM5 and CHIMERE/WRF underestimate the PMv concentrations for January. The difference in PM 10 concentrations for January between CHIMERE/MM5 and CHIMERE/WRF is around a factor 1.6 (PM 10 higher for CHIMERE/MM5). This difference and the larger underestimation in PM 10 concentrations by CHIMERE/WRF are related to the differences in heat fluxes and the resulting PBL heights calculated by WRF. In general the PBL height by WRF meteorology is a factor 2.8 higher at noon in January than calculated by MM5. This study showed that the difference in microphysics scheme has an impact on the profile of cloud liquid water (CLW) calculated by the meteorological driver and therefore on the production of SO 4 aerosol. A sensitivity analysis shows that changing the Noah Land Surface Model (LSM) in our WRF pre-processing for the 5-layer soil temperature model, calculated monthly mean PMv concentrations increase by 30%, due to the change in the heat fluxes and the resulting PBL heights. For June, PM 10 calculated concentrations by CHIMERE/MM5 and CHIMERE/WRF are similar and agree with the observations. Calculated O 3 values for June are in general overestimated by a factor 1.3 by CHIMERE/MM5 and CHIMERE/WRF. High temporal correlations are found between modeled and observed O 3 concentrations.
Keywords	Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	290
Language	English
Publishing date	2009-09-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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