Gravity wave driven seasonal variability of temperature differences between ECMWF IFS and lidar measurements at 54S in the lee of the Southern Andes

2021 ◽  
Author(s):  
Sonja Gisinger ◽  
Inna Polichtchouk ◽  
Robert Reichert ◽  
Andreas Dörnbrack ◽  
Bernd Kaifler ◽  
...  
Keyword(s):  
Energy Density ◽  
Potential Energy ◽  
Southern Hemisphere ◽  
Middle Atmosphere ◽  
Rio Grande ◽  
Winter Half ◽  
Lidar Measurements ◽  
Summer Half ◽  
Ground Based Lidar ◽  
Sponge Layer

<p>In November 2017, the DLR Institute of Atmospheric Physics started running the ground-based Compact Rayleigh Autonomous Lidar (CORAL) at the southern tip of South America in Rio Grande that is located at the east coast of Argentina in the lee of the Andes. We used this independent (i.e., not assimilated in the ECMWF IFS) and high-resolution lidar data of the year 2018 and some individual months in 2019 and 2020 to investigate middle atmosphere temperature deviations in IFS analyses and short-term forecasts at higher mid-latitudes in the southern hemisphere (54 S).</p><p> </p><p>We found a generally good agreement between IFS and CORAL temperature data below 45 km altitude and the calculated monthly mean temperature deviations are smaller than +/-2 K.  The temperature deviations are more variable in time and the sign of the monthly mean deviations varies throughout the year above 45 km altitude. There, the largest positive differences (+2 K), i.e. IFS temperatures were too warm, are found for May 2018. The largest negative differences (-10 K), i.e. IFS temperatures were too cold, are found for August 2018.  The standard deviation of the temperature differences is significantly larger (up to 15 K) and increases with altitude in the winter half year (April to September 2018) compared to the summer half year. The better agreement of IFS temperature with ground-based lidar measurements in the summer months previously reported in literature for the northern hemisphere also manifests for the southern hemisphere and more recent cycles of the IFS. The largest temperature differences above 45 km altitude in the winter half year are due to gravity waves (GWs) and it was found that amplitude and phase deviations are equally important at the location of Rio Grande. In general, the IFS underestimates GW potential energy density in the middle atmosphere, especially within the sponge layer. Monthly mean GW potential energy density at 45-60 km altitude gets up to four times larger when the sponge is removed but is still less than 50 % of the amount of GW potential energy density found in the CORAL data.</p><p> </p>

scholarly journals Lidar temperature series in the middle atmosphere as a reference data set. Part A: Improved retrievals and a 20 year cross-validation of two co-located French lidars

2018 ◽  
Author(s):  
Robin Wing ◽  
Alain Hauchecorne ◽  
Philippe Keckhut ◽  
Sophie Godin-Beekmann ◽  
Sergey Khaykin ◽  
...  
Keyword(s):  
Cross Validation ◽  
Middle Atmosphere ◽  
A Priori ◽  
Treatment Algorithm ◽  
Absolute Temperature ◽  
Atmospheric Composition ◽  
Data Set ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The objective of this paper and its companion (Wing et al., 2018b) is to show that ground based lidar temperatures are a stable, accurate and precise dataset for use in validating satellite temperatures at high vertical resolution. Long-term lidar observations of the middle atmosphere have been conducted at the Observatoire de Haute-Provence (OHP), located in southern France (43.93° N, 5.71° E), since 1978. Making use of 20 years of high-quality co-located lidar measurements we have shown that lidar temperatures calculated using the Rayleigh technique at 532 nm are statistically identical to lidar temperatures calculated from the non-absorbing 355 nm channel of a Differential Absorption Lidar (DIAL) system. This result is of interest to members of the Network for the Detection of Atmospheric Composition Change (NDACC) ozone lidar community seeking to produce validated temperature products. Additionally, we have addressed previously published concerns of lidar-satellite relative warm bias in comparisons of Upper Mesospheric and Lower Thermospheric (UMLT) temperature profiles. We detail a data treatment algorithm which minimizes known errors due to data selection procedures, a priori choices, and initialization parameters inherent in the lidar retrieval. Our algorithm results in a median cooling of the lidar calculated absolute temperature profile by 20 K at 90 km altitude with respect to the standard OHP NDACC lidar temperature algorithm. The confidence engendered by the long-term cross-validation of two independent lidars and the improved lidar temperature dataset is exploited in (Wing et al., 2018b) for use in multi-year satellite validations.

scholarly journals Lidar temperature series in the middle atmosphere as a reference data set – Part 1: Improved retrievals and a 20-year cross-validation of two co-located French lidars

2018 ◽  
Vol 11 (10) ◽  
pp. 5531-5547 ◽  
Author(s):  
Robin Wing ◽  
Alain Hauchecorne ◽  
Philippe Keckhut ◽  
Sophie Godin-Beekmann ◽  
Sergey Khaykin ◽  
...  
Keyword(s):  
Cross Validation ◽  
Middle Atmosphere ◽  
A Priori ◽  
Treatment Algorithm ◽  
Absolute Temperature ◽  
Atmospheric Composition ◽  
Data Set ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The objective of this paper and its companion (Wing et al., 2018) is to show that ground-based lidar temperatures are a stable, accurate, and precise data set for use in validating satellite temperatures at high vertical resolution. Long-term lidar observations of the middle atmosphere have been conducted at the Observatoire de Haute-Provence (OHP), located in southern France (43.93∘ N, 5.71∘ E), since 1978. Making use of 20 years of high-quality co-located lidar measurements, we have shown that lidar temperatures calculated using the Rayleigh technique at 532 nm are statistically identical to lidar temperatures calculated from the non-absorbing 355 nm channel of a differential absorption lidar (DIAL) system. This result is of interest to members of the Network for the Detection of Atmospheric Composition Change (NDACC) ozone lidar community seeking to produce validated temperature products. Additionally, we have addressed previously published concerns of lidar–satellite relative warm bias in comparisons of upper-mesospheric and lower-thermospheric (UMLT) temperature profiles. We detail a data treatment algorithm which minimizes known errors due to data selection procedures, a priori choices, and initialization parameters inherent in the lidar retrieval. Our algorithm results in a median cooling of the lidar-calculated absolute temperature profile by 20 K at 90 km altitude with respect to the standard OHP NDACC lidar temperature algorithm. The confidence engendered by the long-term cross-validation of two independent lidars and the improved lidar temperature data set is exploited in Wing et al. (2018) for use in multi-year satellite validations.

scholarly journals Comparison of NLC particle sizes derived from SCIAMACHY/Envisat observations with ground-based LIDAR measurements at ALOMAR (69° N)

2009 ◽  
Vol 2 (2) ◽  
pp. 1161-1184
Author(s):  
C. von Savigny ◽  
C. E. Robert ◽  
G. Baumgarten ◽  
H. Bovensmann ◽  
J. P. Burrows
Keyword(s):  
Particle Size ◽  
Standard Deviation ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Particle Sizes ◽  
Data Set ◽  
Particle Size Data ◽  
Lidar Measurements ◽  
Ground Based Lidar ◽  
Scanning Imaging

Abstract. SCIAMACHY, the Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY provides measurements of limb-scattered solar radiation in the 220 nm to 2380 nm wavelength range since summer 2002. Measurements in the UV spectral range are well suited for the retrieval of particle sizes of noctilucent clouds (NLCs) and have been used to compile the largest existing satellite data base of NLC particle sizes. This paper presents a comparison of SCIAMACHY NLC size retrievals with the extensive NLC particle size data set based on ground-based LIDAR measurements at the Arctic LIDAR Observatory for Middle Atmosphere Research (ALOMAR, 69° N, 16° E) for the Northern Hemisphere NLC seasons 2003 to 2007. Most of the presented SCIAMACHY NLC particle size retrievals are based on cylindrical particles and a Gaussian particle size distribution with a fixed width. If the differences in spatial as well as vertical resolution between SCIAMACHY and the ALOMAR LIDAR are taken into account, very good agreement is found. The mean particle size derived from SCIAMACHY limb observations for the ALOMAR overpasses in 2003 to 2007 is 56.2 nm with a standard deviation of 12.5 nm, and the LIDAR observations yield a value of 54.2 nm with a standard deviation of 17.4 nm.

scholarly journals Comparison of NLC particle sizes derived from SCIAMACHY/Envisat observations with ground-based LIDAR measurements at ALOMAR (69° N)

2009 ◽  
Vol 2 (2) ◽  
pp. 523-531 ◽  
Author(s):  
C. von Savigny ◽  
C. E. Robert ◽  
G. Baumgarten ◽  
H. Bovensmann ◽  
J. P. Burrows
Keyword(s):  
Particle Size ◽  
Standard Deviation ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Particle Sizes ◽  
Data Set ◽  
Particle Size Data ◽  
Lidar Measurements ◽  
Ground Based Lidar ◽  
Scanning Imaging

Abstract. SCIAMACHY, the Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY has provided measurements of limb-scattered solar radiation in the 220 nm to 2380 nm wavelength range since summer of 2002. Measurements in the UV spectral range are well suited for the retrieval of particle sizes of noctilucent clouds (NLCs) and have been used to compile the largest existing satellite data base of NLC particle sizes. This paper presents a comparison of SCIAMACHY NLC size retrievals with the extensive NLC particle size data set based on ground-based LIDAR measurements at the Arctic LIDAR Observatory for Middle Atmosphere Research (ALOMAR, 69° N, 16° E) for the Northern Hemisphere NLC seasons 2003 to 2007. Most of the presented SCIAMACHY NLC particle size retrievals are based on cylindrical particles and a Gaussian particle size distribution with a fixed width of 24 nm. If the differences in spatial as well as vertical resolution between SCIAMACHY and the ALOMAR LIDAR are taken into account, very good agreement is found. The mean particle size derived from SCIAMACHY limb observations for the ALOMAR overpasses in 2003 to 2007 is 56.2 nm with a standard deviation of 12.5 nm, and the LIDAR observations yield a value of 54.2 nm with a standard deviation of 17.4 nm.

Arctic Lidar Measurements of the Middle Atmosphere

1995 ◽  
pp. 219-222
Author(s):  
D. P. Donovan ◽  
J. A. Whiteway ◽  
W. Steinbrecht ◽  
A. I. Carswell
Keyword(s):  
Middle Atmosphere ◽  
Lidar Measurements

scholarly journals The interdependence of continental warm cloud properties derived from unexploited solar background signals in ground-based lidar measurements

2014 ◽  
Vol 14 (16) ◽  
pp. 8389-8401 ◽  
Author(s):  
J. C. Chiu ◽  
J. A. Holmes ◽  
R. J. Hogan ◽  
E. J. O'Connor
Keyword(s):  
Optical Depth ◽  
Effective Radius ◽  
Liquid Water Path ◽  
Cloud Optical Depth ◽  
Cloud Properties ◽  
Warm Cloud ◽  
Lidar Measurements ◽  
Atmospheric Radiation Measurement ◽  
Ground Based Lidar ◽  
Geometric Thickness

Abstract. We have extensively analysed the interdependence between cloud optical depth, droplet effective radius, liquid water path (LWP) and geometric thickness for stratiform warm clouds using ground-based observations. In particular, this analysis uses cloud optical depths retrieved from untapped solar background signals that are previously unwanted and need to be removed in most lidar applications. Combining these new optical depth retrievals with radar and microwave observations at the Atmospheric Radiation Measurement (ARM) Climate Research Facility in Oklahoma during 2005–2007, we have found that LWP and geometric thickness increase and follow a power-law relationship with cloud optical depth regardless of the presence of drizzle; LWP and geometric thickness in drizzling clouds can be generally 20–40% and at least 10% higher than those in non-drizzling clouds, respectively. In contrast, droplet effective radius shows a negative correlation with optical depth in drizzling clouds and a positive correlation in non-drizzling clouds, where, for large optical depths, it asymptotes to 10 μm. This asymptotic behaviour in non-drizzling clouds is found in both the droplet effective radius and optical depth, making it possible to use simple thresholds of optical depth, droplet size, or a combination of these two variables for drizzle delineation. This paper demonstrates a new way to enhance ground-based cloud observations and drizzle delineations using existing lidar networks.

scholarly journals Graphics algorithm for deriving atmospheric boundary layer heights from CALIPSO data

2018 ◽  
Vol 11 (9) ◽  
pp. 5075-5085 ◽  
Author(s):  
Boming Liu ◽  
Yingying Ma ◽  
Jiqiao Liu ◽  
Wei Gong ◽  
Wei Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Weather Forecasting ◽  
Correlation Coefficients ◽  
Horizontal Resolution ◽  
Backscatter Coefficient ◽  
Distribution Method ◽  
Boundary Layer Height ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The atmospheric boundary layer is an important atmospheric feature that affects environmental health and weather forecasting. In this study, we proposed a graphics algorithm for the derivation of atmospheric boundary layer height (BLH) from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data. Owing to the differences in scattering intensity between molecular and aerosol particles, the total attenuated backscatter coefficient 532 and attenuated backscatter coefficient 1064 were used simultaneously for BLH detection. The proposed algorithm transformed the gradient solution into graphics distribution solution to overcome the effects of large noise and improve the horizontal resolution. This method was then tested with real signals under different horizontal smoothing numbers (1, 3, 15 and 30). Finally, the results of BLH obtained by CALIPSO data were compared with the results retrieved by the ground-based lidar measurements. Under the horizontal smoothing number of 15, 12 and 9, the correlation coefficients between the BLH derived by the proposed algorithm and ground-based lidar were both 0.72. Under the horizontal smoothing number of 6, 3 and 1, the correlation coefficients between the BLH derived by graphics distribution method (GDM) algorithm and ground-based lidar were 0.47, 0.14 and 0.12, respectively. When the horizontal smoothing number was large (15, 12 and 9), the CALIPSO BLH derived by the proposed method demonstrated a good correlation with ground-based lidar. The algorithm provided a reliable result when the horizontal smoothing number was greater than 9. This finding indicated that the proposed algorithm can be applied to the CALIPSO satellite data with 3 and 5 km horizontal resolution.

scholarly journals Spatially Broad Observations of Internal Waves in the Upper Ocean at the Hawaiian Ridge

2006 ◽  
Vol 36 (6) ◽  
pp. 1085-1103 ◽  
Author(s):  
Joseph P. Martin ◽  
Daniel L. Rudnick ◽  
Robert Pinkel
Keyword(s):  
Numerical Model ◽  
Energy Density ◽  
Potential Energy ◽  
Internal Waves ◽  
Upper Ocean ◽  
Mean Square ◽  
The South ◽  
South Side ◽  
Topographic Slope ◽  
Hawaiian Ridge

Abstract The density and current structure at the Hawaiian Ridge was observed using SeaSoar and Doppler sonar during a survey extending from Oahu to Brooks Banks. Across- and along-ridge changes in internal wave statistics in the upper ocean within 200 km of the ridge are investigated. Internal waves with trough-to-crest amplitude as large as 60 m and horizontal wavelength of about 50 km are observed repeatedly in across-ridge sections of potential density. Within 150 km of the ridge, kinetic and potential energy density exceed open-ocean values with maxima about 10 times Garrett–Munk levels. In the Kauai Channel (KC), the kinetic energy density is largest along an M2 internal tide ray. The ray originates at the northern edge of the ridge peak at a large across-ridge change in topographic slope and terminates at the ocean surface about 30–40 km south of the ridge peak. Kinetic and potential energy density are larger on the south side of the ridge at KC, the side with larger topographic slope. Energy density is also larger on the south side of the ridge at KC in numerical model results and on the side of steeper topographic slope in analytical model results. Along the ridge, the largest observed values of mean-square shear and mean-square slope of isopycnal depth are collocated with the largest energy density in numerical model results. Mean-square shear and mean-square slope increase with decreasing bottom depth and with increasing M2 barotropic tidal forcing.

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