scholarly journals Intercomparison and evaluation of ground- and satellite-based stratospheric ozone and temperature profiles above Observatoire de Haute-Provence during the Lidar Validation NDACC Experiment (LAVANDE)

2020 ◽  
Vol 13 (10) ◽  
pp. 5621-5642
Author(s):  
Robin Wing ◽  
Wolfgang Steinbrecht ◽  
Sophie Godin-Beekmann ◽  
Thomas J. McGee ◽  
John T. Sullivan ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
The Other ◽  
Atmospheric Composition ◽  
Temperature Profiles ◽  
Composition Change ◽  
Total Uncertainty ◽  
Broadband Emission ◽  
Uncertainty Estimates ◽  
532 Nm ◽  
Good Agreement

Abstract. A two-part intercomparison campaign was conducted at Observatoire de Haute-Provence (OHP) for the validation of lidar ozone and temperature profiles using the mobile NASA Stratospheric Ozone Lidar (NASA STROZ), satellite overpasses from the Microwave Limb Sounder (MLS), the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), meteorological radiosondes launched from Nîmes, and locally launched ozonesondes. All the data were submitted and compared “blind”, before the group could see results from the other instruments. There was good agreement between all ozone measurements between 20 and 40 km, with differences of generally less than 5 % throughout this region. Below 20 km, SABER and MLS measured significantly more ozone than the lidars or ozonesondes. Temperatures for all lidars were in good agreement between 30 and 60 km, with differences on the order of ±1 to 3 K. Below 30 km, the OHP lidar operating at 532 nm has a significant cool bias due to contamination by aerosols. Systematic, altitude-varying bias up to ±5 K compared to the lidars was found for MLS at many altitudes. SABER temperature profiles are generally closer to the lidar profiles, with up 3 K negative bias near 50 km. Total uncertainty estimates for ozone and temperature appear to be realistic for nearly all systems. However, it does seem that the very low estimated uncertainties of lidars between 30 and 50 km, between 0.1 and 1 K, are not achieved during Lidar Validation Network for the Detection of Atmospheric Composition Change (NDACC) Experiment (LAVANDE). These estimates might have to be increased to 1 to 2 K.

scholarly journals Intercomparison and Evaluation of Ground- and Satellite-Based Stratospheric Ozone and Temperature profiles above Observatoire Haute Provence during the Lidar Validation NDACC Experiment (LAVANDE)

2020 ◽  
Author(s):  
Robin Wing ◽  
Wolfgang Steinbrecht ◽  
Sophie Godin-Beekmann ◽  
Thomas J. McGee ◽  
John T. Sullivan ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
The Other ◽  
Negative Bias ◽  
Temperature Profiles ◽  
Broadband Emission ◽  
Uncertainty Estimates ◽  
532 Nm ◽  
Good Agreement

Abstract. A two-part inter-comparison campaign was conducted at L'Observatoire de Haute Provence (OHP) for the validation of lidar ozone and temperature profiles using the mobile NASA Stratospheric Ozone Lidar (NASA STROZ), satellite overpasses from the Microwave Limb Sounder (MLS), the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), meteorological radiosondes launched from Nimes, and locally launched ozonesondes. All the data were submitted and compared blind, before the group could see results from the other instruments. There was good agreement between all ozone measurements between 20 and 40 km with differences of generally less than 5 % throughout this region. Below 20 km SABER and MLS measured significantly more ozone than the lidars or ozone sondes. Temperatures for all lidars were in good agreement between 30 and 60 km with differences on the order of ±1 to 3 K. Below 30 km, the OHP lidar operating at 532 nm has a significant cool bias due to contamination by aerosols. Systematic, altitude varying bias up to ±5 K compared to the lidars was found for MLS at many altitudes. SABER temperature profiles are generally closer to the lidar profiles, with up 3 K negative bias near 50 km. Uncertainty estimates for ozone and temperature appear to be realistic for nearly all systems. However, it does seem that the very low estimated uncertainties of lidars between 30 and 50 km, between 0.1 and 1 K, are not achieved during LidAr VAlidation NDacc Experiment (LAVANDE). These estimates might have to be increased to 1 to 2 K.

scholarly journals Evaluation of the new DWD ozone and temperature lidar during the Hohenpeißenberg Ozone Profiling Study (HOPS) and comparison of results with previous NDACC campaigns

2021 ◽  
Vol 14 (5) ◽  
pp. 3773-3794
Author(s):  
Robin Wing ◽  
Sophie Godin-Beekmann ◽  
Wolfgang Steinbrecht ◽  
Thomas J. McGee ◽  
John T. Sullivan ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Composition Change ◽  
Broadband Emission ◽  
Goddard Space Flight Center ◽  
Meteorological Observatory ◽  
Lidar Measurements ◽  
Region Temperature ◽  
Relative Differences ◽  
Good Agreement

Abstract. A newly upgraded German Weather Service (DWD) ozone and temperature lidar (HOH) located at the Hohenpeißenberg Meteorological Observatory (47.8∘ N, 11.0∘ E) has been evaluated through comparison with the travelling standard lidar operated by NASA's Goddard Space Flight Center (NASA GSFC Stratospheric Ozone (STROZ) lidar), satellite overpasses from the Microwave Limb Sounder (MLS), the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), the Ozone Mapping and Profiler Suite (OMPS), meteorological radiosondes launched from Munich (65 km northeast), and locally launched ozonesondes. The “blind” evaluation was conducted under the framework of the Network for the Detection of Atmospheric Composition Change (NDACC) using 10 clear nights of measurements in 2018 and 2019. The campaign, referred to as the Hohenpeißenberg Ozone Profiling Study (HOPS), was conducted within the larger context of NDACC validation activities for European lidar stations. There was good agreement between all ozone lidar measurements in the range of 15 to 41 km with relative differences between co-located ozone profiles of less than ±10 %. Differences in the measured ozone number densities between the lidars and the locally launched ozone sondes were also generally less than 5 % below 30 km. The satellite ozone profiles demonstrated some differences with respect to the ground-based lidars which are due to sampling differences and geophysical variation. Both the original and new DWD lidars continue to meet the NDACC standard for lidar ozone profiles by exceeding 3 % accuracy between 16.5 and 43 km. Temperature differences for all instruments were less than ±5 K below 60 km, with larger differences present in the lidar–satellite comparisons above this region. Temperature differences between the DWD lidars met the NDACC accuracy requirements of ±1 K between 17 and 78 km. A unique cross-comparison between the HOPS campaign and a similar, recent campaign at Observatoire de Haute-Provence (Lidar Validation NDACC Experiment; LAVANDE) allowed for an investigation into potential biases in the NASA-STROZ reference lidar. The reference lidar may slightly underestimate ozone number densities above 43 km with respect to the French and German NDACC lidars. Below 20 km, the reference lidar temperatures profiles are 5 to 10 K cooler than the temperatures which are reported by the other instruments.

scholarly journals Technical Note: Validation of Odin/SMR limb observations of ozone, comparisons with OSIRIS, POAM III, ground-based and balloon-borne instruments

2008 ◽  
Vol 8 (1) ◽  
pp. 727-779
Author(s):  
F. Jégou ◽  
J. Urban ◽  
J. de La Noë ◽  
P. Ricaud ◽  
E. Le Flochmoën ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Technical Note ◽  
Atmospheric Composition ◽  
Satellite Measurements ◽  
Space Agency ◽  
Infrared Imager ◽  
Ozone Maximum ◽  
Polar Ozone ◽  
Good Agreement

Abstract. The Odin satellite carries two instruments capable of determining stratospheric ozone profiles by limb sounding: the Sub-Millimetre Radiometer (SMR) and the UV-visible spectrograph of the OSIRIS (Optical Spectrograph and InfraRed Imager System) instrument. A large number of ozone profiles measurements were performed during six years from November 2001 to present. This ozone dataset is here used to make quantitative comparisons with satellite measurements in order to assess the quality of the Odin/SMR ozone measurements. In a first step, we compare Swedish SMR retrievals version 2.1, French SMR ozone retrievals version 222 (both from the 501.8 GHz band), and the OSIRIS retrievals version 3.0, with the operational version 4.0 ozone product from POAM III (Polar Ozone Atmospheric Measurement). In a second step, we refine the Odin/SMR validation by comparisons with ground-based instruments and balloon-borne observations. We use observations carried out within the framework of the Network for Detection of Atmospheric Composition Change (NDACC) and balloon flight missions conducted by the Canadian Space Agency (CSA), the Laboratoire de Physique et de Chimie de l'Environnement (LPCE, Orléans, France), and the Service d'Aéronomie (SA, Paris, France). Coincidence criteria were 5° in latitude x in 10° longitude, and 5 h in time in Odin/POAM III comparisons, 12 h in Odin/NDACC comparisons, and 72 h in Odin/balloons comparisons. An agreement is found with the POAM III experiment (10–60 km) within −0.3±0.2 ppmv (bias±standard deviation) for SMR (v222, v2.1) and within −0.5±0.2 ppmv for OSIRIS (v3.0). Odin ozone mixing ratio products are systematically slightly lower than the POAM III data and show an ozone maximum lower by 1–5 km in altitude. The comparisons with the NDACC data (10–34 km for ozonesonde, 10–50 km for lidar, 10–60 for microwave instruments) yield a good agreement within −0.15±0.3 ppmv for the SMR data and −0.3±0.3 ppmv for the OSIRIS data. Finally the comparisons with instruments on large balloons (10–31 km) show a good agreement, within −0.7±1 ppmv.

scholarly journals Long-term (1999–2019) variability of stratospheric aerosol over Mauna Loa, Hawaii, as seen by two co-located lidars and satellite measurements

2020 ◽  
Vol 20 (11) ◽  
pp. 6821-6839 ◽  
Author(s):  
Fernando Chouza ◽  
Thierry Leblanc ◽  
John Barnes ◽  
Mark Brewer ◽  
Patrick Wang ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
Orthogonal Polarization ◽  
Mauna Loa ◽  
Quiescent Period ◽  
Level 3 ◽  
The Impact ◽  
Good Agreement

Abstract. As part of the Network for the Detection of Atmospheric Composition Change (NDACC), ground-based measurements obtained from the Jet Propulsion Laboratory (JPL) stratospheric ozone lidar and the NOAA stratospheric aerosol lidar at Mauna Loa, Hawaii, over the past 2 decades were used to investigate the impact of volcanic eruptions and pyrocumulonimbus (PyroCb) smoke plumes on the stratospheric aerosol load above Hawaii since 1999. Measurements at 355 and 532 nm conducted by these two lidars revealed a color ratio of 0.5 for background aerosols and small volcanic plumes and 0.8 for a PyroCb plume recorded on September 2017. Measurements of the Nabro plume by the JPL lidar in 2011–2012 showed a lidar ratio of (64±12.7) sr at 355 nm around the center of the plume. The new Global Space-based Stratospheric Aerosol Climatology (GloSSAC), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) Level 3 and Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III-ISS) stratospheric aerosol datasets were compared to the ground-based lidar datasets. The intercomparison revealed a generally good agreement, with vertical profiles of extinction coefficient within 50 % discrepancy between 17 and 23 km above sea level (a.s.l.) and 25 % above 23 km a.s.l. The stratospheric aerosol depth derived from all of these datasets shows good agreement, with the largest discrepancy (20 %) being observed between the new CALIOP Level 3 and the other datasets. All datasets consistently reveal a relatively quiescent period between 1999 and 2006, followed by an active period of multiple eruptions (e.g., Nabro) until early 2012. Another quiescent period, with slightly higher aerosol background, lasted until mid-2017, when a combination of extensive wildfires and multiple volcanic eruptions caused a significant increase in stratospheric aerosol loading. This loading maximized at the very end of the time period considered (fall 2019) as a result of the Raikoke eruption, the plume of which ascended to 26 km altitude in less than 3 months.

scholarly journals Intercomparison of stratospheric ozone and temperature profiles during the October 2005 Hohenpeißenberg Ozone Profiling Experiment (HOPE)

2009 ◽  
Vol 2 (1) ◽  
pp. 125-145 ◽  
Author(s):  
W. Steinbrecht ◽  
T. J. McGee ◽  
L. W. Twigg ◽  
H. Claude ◽  
F. Schönenborn ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Cold Bias ◽  
Lidar Data ◽  
Temperature Profiles ◽  
Background Estimation ◽  
Temperature Bias ◽  
North East ◽  
Range Error ◽  
Better Than

Abstract. Thirteen clear nights in October 2005 allowed successful intercomparison of the lidar operated since 1987 by the German Weather Service (DWD) at Hohenpeißenberg (47.8° N, 11.0° E) with the Network for the Detection of Atmospheric Composition Change (NDACC) travelling standard lidar operated by NASA's Goddard Space Flight Center. Both lidars provide ozone profiles in the stratosphere, and temperature profiles in the strato- and mesosphere. Additional ozone profiles came from on-site Brewer/Mast ozonesondes, additional temperature profiles from Vaisala RS92 radiosondes launched at Munich (65 km north-east), and from operational analyses by the US National Centers for Environmental Prediction (NCEP). The intercomparison confirmed a low bias for ozone from the DWD lidar in the 33 to 43 km region, by up to 10%. This bias is caused by the DWD ozone algorithm, and is consistent with previous comparisons of the DWD lidar with SAGE, GOMOS and other instruments. During HOPE, precision (repeatability) for ozone data from both lidars was better than 5% between 20 and 40 km altitude, dropping to 10% near 45 km, and to 50% near 50 km. These results are consistent with previous NDACC intercomparisons, and confirm the reliability of the NASA NDACC travelling standard lidar. Temperature from the DWD lidar showed a 1 to 2 K cold bias from 30 to 65 km against the NASA lidar, and a 2 to 4 K cold bias against radiosondes and NCEP. This is also consistent with previous intercomparisons. Temperature precision (repeatability) for the DWD lidar was better than 2 K from 30 to 50 km, decreasing to 10 K near 70 km. For the NASA lidar, precision is expected to be better than 1 K over the 30 to 70 km range. However, due to the much lower temperature precision of the DWD lidar, this could not be checked during HOPE. It was noted that the current DWD algorithm over-estimates temperature uncertainty, which should be reduced by a factor of 2.2 (e.g. from 22 K to 10 K near 70 km). The HOPE intercomparison did uncover a 290 m range error (upward shift) of the DWD lidar data. When this shift is removed, the bias of the ozone algorithm is corrected, and a better background estimation is used, ozone profiles from the DWD lidar agree very well with both the NASA lidar and SAGE. Systematic differences are then smaller than 3% between 20 and 44 km, and smaller than 5% between 17 and 47 km. These differences are close to zero, and are not (statistically) significant. The cold temperature bias against the NASA lidar also disappears when the DWD temperature processing is corrected for the 290 m range error, and more appropriate values for the Earth's gravity acceleration are used. Compared to the radiosondes or NCEP analyses, however, both lidars show 1 to 2 K lower temperatures over the entire 15 to 35 km range. Temperature and ozone variations are tracked well by both lidars, by ozone- and radiosondes, and by NCEP analyses. Correlations exceed 0.8 to 0.9 at most stratospheric levels. They decrease at levels above 40 km, especially for ozone or NCEP temperature. The ozone and temperature bias of the DWD lidar does not appear to have changed over time. Records of ozone and temperature from the DWD lidar should be consistent over the years. Nevertheless, the HOPE intercomparison was instrumental in uncovering and repairing several long-standing errors. HOPE also confirmed the reliability of the NASA lidar as a travelling standard. Now the entire DWD lidar data record needs to be reprocessed with the improved and revised algorithms.

scholarly journals Unusual stratospheric ozone anomalies observed in 22 years of measurements from Lauder, New Zealand

2015 ◽  
Vol 15 (4) ◽  
pp. 5241-5267
Author(s):  
G. E. Nedoluha ◽  
I. S. Boyd ◽  
A. Parrish ◽  
R. M. Gomez ◽  
D. R. Allen ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Sharp Increase ◽  
Stratospheric Ozone ◽  
Sharp Decrease ◽  
Atmospheric Composition ◽  
Composition Change ◽  
Anticyclonic Circulation ◽  
Latitude Band ◽  
Mixing Ratios

Abstract. The Microwave Ozone Profiling Instrument (MOPI1) has provided ozone (O3) profiles for the Network for the Detection of Atmospheric Composition Change (NDACC) at Lauder, New Zealand, since 1992. We present the entire 22 year dataset and compare with satellite O3 observations. We will study in detail two particularly interesting variations in O3. The first is a large positive O3 anomaly which occurs in the mid-stratosphere at ~10–30 hPa in June 2001, and which is caused by an anticyclonic circulation that persists for several weeks over Lauder. We find that this O3 anomaly is associated with air with the highest June average tracer equivalent latitude (TrEL) over the 35 year period (1980–2014). A second, and longer-lived feature, is a positive O3 anomaly in the mid-stratosphere (~10 hPa) from mid-2009 until mid-2013. Coincident measurements from the Aura Microwave Limb Sounder (MLS) show that these high O3 mixing ratios are well correlated with high nitrous oxide (N2O) mixing ratios. This correlation suggests that the high O3 over this 4 year period is driven by unusual dynamics. The beginning of the high O3 and high N2O period at Lauder (and throughout this latitude band) occurs nearly simultaneously with a~sharp decrease in O3 and N2O at the equator, and the period ends nearly simultaneously with a~sharp increase in O3 and N2O at the equator.

NDACC Lidar Validation Activities in Europe

2020 ◽  
Author(s):  
Robin Wing ◽  
Wolfgang Steinbrecht ◽  
Sophie Godin-Beekmann ◽  
Thomas J. McGee ◽  
John Sullivan ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Uncertainty Budget ◽  
Small Scale ◽  
Statistical Techniques ◽  
Ncep Reanalysis ◽  
Broadband Emission ◽  
Meteorological Observatory ◽  
Intercomparison Exercises ◽  
Good Agreement ◽  
Balloon Measurements

<p>Recent intercomparison exercises have been conducted at two European NDACC lidar sites.  The mobile NASA Stratospheric Ozone Lidar (NASA STROZ) was present for a two part validation campaign at the Observatoire de Haute-Provence (43.93 N, 5.71 E) in July 2017 and March 2018 and at the Hohenpeißenberg Meteorological Observatory (47.80 N, 11.00 E) in March 2019.  Lidar profiles of ozone and temperature were compared with local radiosondes and ozonesondes; satellite profiles from local overpasses of Sounding of the Atmosphere by Broadband Emission Radiometry instrument (SABER) and Microwave Limb Sounder (MLS); and NCEP reanalysis. There is overall good agreement between all the lidar instruments and the balloon measurements, particularly in the reproduction of small scale features, during all three phases of the European campaign.  </p><p>We have conducted a detailed correlational study of all instruments involved in the campaign and have rigorously evaluated the uncertainty budget of each instrument.  We will discuss the strengths and drawbacks of different statistical techniques for evaluating coincident ozone and temperature measurements and compare how our estimates of instrument uncertainty compare to the observed variance in the data.</p>

scholarly journals The diurnal variation in stratospheric ozone from the MACC reanalysis, the ERA-Interim reanalysis, WACCM and Earth observation data: characteristics and intercomparison

2014 ◽  
Vol 14 (23) ◽  
pp. 32667-32708 ◽  
Author(s):  
A. Schanz ◽  
K. Hocke ◽  
N. Kämpfer ◽  
S. Chabrillat ◽  
A. Inness ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
High Latitude ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Atmospheric Tides ◽  
Valuable Insight ◽  
Observation Data ◽  
Free Running ◽  
Good Agreement

Abstract. In this study we compare the diurnal variation in stratospheric ozone derived from free-running simulations of the Whole Atmosphere Community Climate Model (WACCM) and from reanalysis data of the atmospheric service MACC (Monitoring Atmospheric Composition and Climate) which both use a similar stratospheric chemistry module. We find good agreement between WACCM and the MACC reanalysis for the diurnal ozone variation in the high-latitude summer stratosphere based on photochemistry. In addition, we consult the ozone data product of the ERA-Interim reanalysis. The ERA-Interim reanalysis ozone system with its long-term ozone parametrization can not capture these diurnal variations in the upper stratosphere that are due to photochemistry. The good dynamics representations, however, reflects well dynamically induced ozone variations in the lower stratosphere. For the high-latitude winter stratosphere we describe a novel feature of diurnal variation in ozone where changes of up to 46.6% (3.3 ppmv) occur in monthly mean data. For this effect good agreement between the ERA-Interim reanalysis and the MACC reanalysis suggest quite similar diurnal advection processes of ozone. The free-running WACCM model seriously underestimates the role of diurnal advection processes at the polar vortex at the two tested resolutions. The intercomparison of the MACC reanalysis and the ERA-Interim reanalysis demonstrates how global reanalyses can benefit from a chemical representation held by a chemical transport model. The MACC reanalysis provides an unprecedented description of the dynamics and photochemistry of the diurnal variation of stratospheric ozone which is of high interest for ozone trend analysis and research on atmospheric tides. We confirm the diurnal variation in ozone at 5 hPa by observations of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) experiment and selected sites of the Network for Detection of Atmospheric Composition Change (NDACC). The latter give valuable insight even to diurnal variation of ozone in the polar winter stratosphere.

scholarly journals Intercomparison of stratospheric ozone and temperature profiles during the October 2005 Hohenpeissenberg Ozone Profiling Experiment (HOPE)

2009 ◽  
Vol 2 (1) ◽  
pp. 37-86
Author(s):  
W. Steinbrecht ◽  
T. J. McGee ◽  
L. W. Twigg ◽  
H. Claude ◽  
F. Schönenborn ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Cold Bias ◽  
Lidar Data ◽  
Temperature Profiles ◽  
Temperature Bias ◽  
North East ◽  
Future Version ◽  
Environmental Prediction ◽  
Better Than

Abstract. Thirteen clear nights in October 2005 allowed successful intercomparison of the stationary lidar operated since 1987 by the German Weather Service (DWD) at Hohenpeissenberg (47.8° N, 11.0° E) with the Network for the Detection of Atmospheric Composition Change (NDACC) travelling standard lidar operated by NASA's Goddard Space Flight Center. Both lidars provide ozone profiles in the stratosphere, and temperature profiles in the strato- and mesosphere. Additional ozone profiles came from on-site Brewer/Mast ozonesondes, additional temperature profiles from Vaisala RS92 radiosondes launched at Munich (65 km north-east), and from operational analyses by the US National Centers for Environmental Prediction (NCEP). The intercomparison confirmed a low bias for ozone from the DWD lidar in the 33 to 43 km region, by up to 10%. This bias is caused by the DWD ozone algorithm. It will be removed in a future version. Between 20 and 33 km, agreement between both lidars, and ozonesondes below 30 km, is good with ozone differences less than 3 to 5%. Results are consistent with previous comparisons of the DWD lidar with SAGE, GOMOS and other satellite instruments. The intercomparison did uncover a 290 m upward shift of the DWD lidar data. When this shift is removed, agreement with ozone from the NASA lidar improves below 20 km, with remaining differences usually less than 5%, and not statistically significant. Precision (repeatability) for the lidar ozone data is better than 5% between 20 and 40 km altitude, dropping to 10% near 45 km, and 50% near 50 km. Temperature from the DWD lidar has a 1 to 2 K cold bias from 30 to 65 km against the NASA lidar, and a 2 to 4 K cold bias against radiosondes and NCEP. This is consistent with previous intercomparisons against NCEP or radiosondes. The cold bias against the NASA lidar disappears when the DWD lidar data are corrected for the afore-mentioned 290 m range error, and more appropriate values for the Earth's gravity acceleration are used. Temperature precision (repeatability) for the DWD lidar is better than 2 K between 30 and 50 km , decreasing to 10 K near 70 km. It is over-estimated by the current DWD algorithm, and should be reduced by a factor of 2.2 (e.g. from 22 K to 10 K near 70 km). Temperature and ozone variations are tracked well by both lidars, by ozone- and radiosondes, and by NCEP analyses. Correlations exceed 0.8 to 0.9 at most stratospheric levels. They decrease at levels above 40 km, especially for ozone or NCEP temperature. The ozone and temperature bias of the DWD lidar does not appear to have changed over the years. Long-term records of ozone and temperature from the DWD lidar should be consistent. Nevertheless, the HOPE intercomparison was instrumental in uncovering several long-standing errors. These need to be fixed and the entire DWD lidar data record needs to be reprocessed.

scholarly journals Long-term (1999–2019) variability of stratospheric aerosol over Mauna Loa, Hawaii, as seen by two co-located lidars and satellite measurements

2020 ◽  
Author(s):  
Fernando Chouza ◽  
Thierry Leblanc ◽  
John Barnes ◽  
Mark Brewer ◽  
Patrick Wang ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
Mauna Loa ◽  
Quiescent Period ◽  
Level 3 ◽  
Ground Based Lidar ◽  
The Impact ◽  
Good Agreement

Abstract. As part of the Network for the Detection of Atmospheric Composition Change (NDACC), ground-based measurements obtained from the Jet Propulsion Laboratory (JPL) stratospheric ozone lidar and the NOAA stratospheric aerosol lidar at Mauna Loa, Hawaii over the past two decades were used to investigate the impact of volcanic eruptions and pyro-cumulonimbus smoke plumes on the stratospheric aerosol load above Hawaii since 1999. Measurements at 355 nm and 532 nm conducted by these two lidars revealed Ångström exponents of −1.6 for background plumes and −0.6 for a PyroCb plume recorded on September 2017. Measurements of the Nabro plume by the JPL lidar in 2011/2012 showed a lidar ratio of (64 ± 12.7) sr at 355 nm around the center of the plume. The new GloSSAC, CALIOP Level 3 and SAGE III-ISS stratospheric aerosol datasets were compared to the ground-based lidar datasets. The intercomparison revealed a generally good agreement, with vertical profiles of extinction coefficient within 50 % of discrepancy between 17 km and 23 km above sea level (ASL), and 25 % above 23 km ASL. The stratospheric aerosol depth derived from all these datasets shows good agreement, with the largest discrepancy (20 %) being observed between the new CALIOP Level 3 and the other datasets. All datasets consistently reveal a relatively quiescent period between 1999 and 2005, followed by an active period of multiple eruptions (e.g., Nabro) until early 2012. Another quiescent period, with slightly higher aerosol background, lasted until mid-2017, when a combination of extensive wildfires and multiple volcanic eruptions caused a significant increase in stratospheric aerosol loading. This loading maximized at the very end of the time period considered (fall 2019) as a result of the Raikoke eruption, the plume of which ascended to 26 km altitude in less than three months.

Sign in / Sign up

Export Citation Format

Share Document