NASA's Goddard Space Flight Center (GSFC) transported two lidar instruments to the NOAA facility at the Mauna Loa Observatory (MLO) on the Big Island of Hawaii, to participate in an official, extended validation campaign. This site is situated 11,141 ft. above sea level on the side of the mountain. The observatory has been making atmospheric measurements regularly since the 1950's, and has hosted the GSFC Stratospheric Ozone (STROZ) Lidar and the GSFC Aerosol and Temperature (AT) Lidar on several occasions, most recently between November, 2012 and November, 2015. The purpose of this extended deployment was to participate in Network for the Detection of Atmospheric Composition Change (NDACC) Validation campaigns with the JPL Stratospheric Ozone Lidar and the NOAA Temperature, Aerosol and Water Vapor instruments as part of the routine NDACC Validation Protocol.

In traditional validations of atmospheric profiles, the intercomparison of two datasets is usually carried out in predefined groups of observational characteristic like longitude, stellar magnitude or solar zenith angle. Here we present an alternative method in which we trained a self organizing map (SOM) with a full time series of relative difference profiles of SCIAMACHY limb v5.02 and ozone profiles from seven NDACC lidar. For each individual observation, a set of observations characteristics from the SCIAMACHY and lidar data was mapped to the trained SOM. These maps were studied to see if the variation for a given characteristic corresponds to the variation seen in the SOM map. For the studied datasets, altitude-dependent relations for the global dataset were found between the difference profiles and studied variables. From the lowest altitude studied (18 km) ascending, the most influencing factors were found to be longitude, followed by solar zenith angle and latitude, sensor age and again solar zenith angle together with the day of the year at the highest altitudes studied here (up to 45 km). Clustering into three classes showed that there are also some local dependencies, with for instance one cluster having a much stronger correlation with the sensor age (days since launch) between 36 and 42 km. The validation approach based on using SOM proved to be a powerful tool for the exploration of differences between datasets without being limited to a-priori defined data subsets.

Numerous vertical ozone profile data records collected over the past decades from space-based platforms have the potential to allow the ozone and climate communities to tackle a variety of research questions. A prime topic is the study and documentation of long-term changes in the vertical distribution of atmospheric ozone, as targeted by the recent SPARC/IO3C/IGACO-O3/NDACC Initiative (SI2N) and WMO’s ozone assessment. Such studies typically require data records with documented mutual consistency in terms of bias and long-term stability. Ground-based networks play a pivotal role in evaluating which satellite records comply with end-user requirements and are fit for their purpose. They provide high-quality, independent measurements on a pseudo- global scale from the ground up to the stratosphere. Here, we present an assessment of the long-term stability and mutual consistency of fourteen limb/occultation ozone profile data records, using NDACC/GAW/SHADOZ ozonesonde and NDACC lidar network data as reference standards. We show how a harmonized analysis framework and robust statistical methods allow us to derive reliable estimates of the drift, bias, and short-term variability of each satellite data record. We examine the dependence of these parameters on altitude and, whenever feasible, on latitude and season. The analysis is furthermore performed in four different ozone profile representations, as it turns out that auxiliary data used for unit and representation conversions can impact data quality. We discuss the mutual consistency and compliance of satellite data sets with respect to specific user requirements from GCOS and from climate research groups. We conclude by reflecting on the implication of our results for trend assessments on recently merged ozone profile records (Ozone_CCI, GOZCARDS, SWOOSH, ...)

Drifts, trends and periodic variations were calculated from monthly zonally averaged ozone profiles. The ozone profiles were derived from level-1b data of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) by means of the scientific level-2 processor run by the Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research (IMK). All trend and drift analyses were performed using a multilinear parametric trend model which includes a linear term, several harmonics with period lengths from 3 to 24 months and the quasi-biennial oscillation (QBO). Drifts at 2-sigma significance level were mainly negative for ozone relative to Aura MLS and Odin OSIRIS and negative or near zero for most of the comparisons to lidar measurements. Lidar stations used here include those at Hohenpeissenberg (47.8° N, 11.0° E), Lauder (45.0° S, 169.7° E), Mauna Loa (19.5° N, 155.6° W), Observatoire Haute Provence (43.9° N, 5.7° E) and Table Mountain (34.4° N, 117.7° W). Drifts against the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) were found to be mostly insignificant. The assessed MIPAS ozone trends cover the time period of July 2002 to April 2012 and range from −0.56 ppmv decade−1 to +0.48 ppmv decade−1 (−0.52 ppmv decade−1 to +0.47 ppmv decade−1 when displayed on pressure coordinates) depending on altitude/pressure and latitude. From the empirical drift analyses we conclude that the real ozone trends might be slightly more positive/less negative than those calculated from the MIPAS data, by conceding the possibility of MIPAS having a very small (approximately within −0.3 ppmv decade−1) negative drift for ozone. This leads to drift-corrected trends of −0.41 ppmv decade−1 to +0.55 ppmv decade−1 (−0.38 ppmv decade−1 to +0.53 ppmv decade−1 when displayed on pressure coordinates) for the time period covered by MIPAS Envisat measurements, with very few negative and large areas of positive trends at mid-latitudes for both hemispheres around and above 30 km (~10 hPa). Negative trends are found in the tropics around 25 and 35 km (~25 and 5 hPa), while an area of positive trends is located right above the tropical tropopause. These findings are in good agreement with the recent literature. Differences of the trends compared with the recent literature could be explained by a possible shift of the subtropical mixing barriers. Results for the altitude–latitude distribution of amplitudes of the quasi-biennial, annual and the semi-annual oscillation are overall in very good agreement with recent findings.

Thanks to the Montreal Protocol, the decline of stratospheric ozone has been stopped. Ozone has now started to recover. The Kyoto Protocol, however, has been less successful. CO2 levels keep increasing, the stratosphere keeps cooling. Among other things, this cooling does affect ozone recovery. What can data from just a few NDACC stations tell us about these long-term changes? In our presentation we will look at long-term variations of stratospheric ozone and temperature since the 1960s. We will show results from NDACC stations and from Europe, and will put those into the context of global observations. At Hohenpeissenberg (47.8°N, 11.0°E), ozone in the upper stratosphere (40km / 2hPa) has been increasing since about 2000, by almost 10%. Levels are already comparable to what was measured in the late 1980s. At the same time, temperature has been declining substantially since about 2000, by more than 3 K. Total ozone, where variations are coming mostly from the lower stratosphere, has been increasing since the mid 1990s at Hohenpeissenberg. This increase, and the previous decline, largely track the evolution of Equivalent Effective Stratospheric Chlorine (EESC). Superimposed are natural variations, which were particularily large in 2010 and 2011. 2010 had very large ozone columns, comparable to the early 1980s. 2011, on the other hand, was a year with very low ozone columns, and with unprecedented large ozone losses in Arctic spring. At Hohenpeissenberg, the total ozone annual mean of 2011 was the 3rd lowest on record since 1968. Only 1992 and 1993, after the Pinatubo eruption, had lower ozone columns. Multiple linear regression analysis indicates that this large swing from 2010 to 2011 is connected to meteorological changes, i.e. the change of the Arctic Oscillation from pronounced negative phase in 2010, to pronounced positive phase in 2011.

The long-term evolution of stratospheric ozone at different stations in the low and mid-latitudes is investigated. The analysis is performed by comparing the collocated profiles of ozone lidars, at the northern mid-latitudes (Meteorological Observatory Hohenpeißenberg, Haute-Provence Observatory, Tsukuba and Table Mountain Facility), tropics (Mauna Loa Observatory) and southern mid-latitudes (Lauder), with ozonesondes and space-borne sensors (SBUV(/2), SAGE II, HALOE, UARS MLS and Aura MLS), extracted around the stations. Relative differences are calculated to find biases and temporal drifts in the measurements. All measurement techniques show their best agreement with respect to the lidar at 20–40 km, where the differences and drifts are generally within ±5% and ±0.5% yr−1, respectively, at most stations. In addition, the stability of the long-term ozone observations (lidar, SBUV(/2), SAGE II and HALOE) is evaluated by the cross-comparison of each data set. In general, all lidars and SBUV(/2) exhibit near-zero drifts and the comparison between SAGE II and HALOE shows larger, but insignificant drifts. The RMS of the drifts of lidar and SBUV(/2) is 0.22 and 0.27% yr−1, respectively at 20–40 km. The average drifts of the long-term data sets, derived from various comparisons, are less than ±0.3% yr−1 in the 20–40 km altitude at all stations. A combined time series of the relative differences between SAGE II, HALOE and Aura MLS with respect to lidar data at six sites is constructed, to obtain long-term data sets lasting up to 27 years. The relative drifts derived from these combined data are very small, within ±0.2% yr−1.

For 20 years the Naval Research Laboratory has been making continuous water vapor profile measurements at 22.235 GHz with the Water Vapor Millimeter‐Wave Spectrometer (WVMS) instruments, with the program expanding from one to three instruments in the first 6 years. Since the initial deployments there have been gradual improvements in the instrument design which have improved data quality and reduced maintenance requirements. Recent technological developments have made it possible to entirely redesign the instrument and improve not only the quality of the measurements but also the capability of the instrument. We present the fourth‐generation instrument now operating at Table Mountain, California, which incorporates the most recent advances in microwave radiometry. This instrument represents the most significant extension of our measurement capability to date, enabling us to measure middle atmospheric water vapor from ∼26–80 km.

The long-term temperature profile data sets obtained by Rayleigh lidars at three different northern latitudes within the Network for the Detection of Atmospheric Composition Change were used to derive the middle atmosphere temperature trend and response to the 11 year solar cycle. The lidars were located at the Mauna Loa Observatory, Hawaii (MLO, 19.5 degrees N); the Table Mountain Facility, California (TMF, 34.4 degrees N); and the Observatoire de Haute Provence, France (OHP, 43.9 degrees N). A stratospheric cooling trend of 2-3 K/decade was found for both TMF and OHP, and a trend of <= 0.5 +/- 0.5 K/decade was found at MLO. In the mesosphere, the trend at TMF (3-4 K/decade) was much larger than that at both OHP and MLO (<1 K/decade). The lidar trends agree well with earlier satellite and rocketsonde trends in the stratosphere, but a substantial discrepancy was found in the mesosphere. The cooling trend in the upper stratosphere at OHP during 1981-1994 (similar to 2-3 K/decade) was much larger than that during 1995-2009 (<= 0.8 K/decade), coincident with the slightly increasing upper stratospheric ozone density after 1995. Significant temperature response to the 11 year solar cycle was found. The correlation was positive in both the stratosphere and mesosphere at MLO and TMF. At OHP a wintertime negative response in the upper stratosphere and a positive response in the middle mesosphere were observed during 1981-1994, but the opposite behavior was found during 1995-2009. This behavior may not be a direct solar cycle response at all but is likely related to an apparent response to decadal variability (e.g., volcanoes, modulated random occurrence of sudden stratospheric warmings) that is more complex.

Abstract. Recognizing the importance of water vapor in the upper troposphere and lower stratosphere (UT/LS) and the scarcity of high-quality, long-term measurements, JPL began the development of a powerful Raman lidar in 2005 to try to meet these needs. This development was endorsed by the Network for the Detection of Atmospheric Composition Change (NDACC) and the validation program for the EOS-Aura satellite. In this paper we review the stages in the instrumental development of the lidar and the conclusions from three validation campaigns: MOHAVE, MOHAVE-II, and MOHAVE 2009 (Measurements of Humidity in the Atmosphere and Validation Experiments). The data analysis, profile retrieval and calibration procedures, as well as additional results from MOHAVE-2009 are presented in detail in a companion paper (Leblanc et al., 2011a). Ultimately the lidar has demonstrated capability to measure water vapor profiles from ~1 km above the ground to the lower stratosphere, reaching 14 km for 1-h integrated profiles and 21 km for 6-h integrated profiles, with a precision of 10 % or better near 13 km and below, and an estimated accuracy of 5 %.

The seasonal and interannual variability of gravity wave (GW) variance in the upper stratosphere (35–50 km) and lower mesosphere (48–63 km) has been studied using 10.5 years (January 1997 to June 2007) of temperature profile results obtained with the Jet Propulsion Laboratory Rayleigh lidar at Mauna Loa Observatory, Hawaii (19.5°N, 155.6°W). Seasonal variability with a maximum in winter and a minimum in summer was observed in the upper stratosphere, suggesting dominance of the annual oscillation. In the lower mesosphere the seasonal oscillations of GW variance were dominated by a semiannual oscillation (SAO), likely due to the selective filtering of GWs by the tropical upper stratospheric SAO wind. Modulation of GW variance by the quasi‐biennial oscillation was clearly present only for the long vertical wavelength band in the upper stratosphere, and not in the lower mesosphere. The United Kingdom Met Office zonal mean zonal wind further supports that enhanced GW activity in the upper stratosphere corresponds to the westerly shear phase of the zonal wind at 10 hPa (∼30 km), and suppressed activity corresponds to the easterly shear phase. During the strong El Niño event in the winter of 1997–1998, enhanced GW activity was observed only in the lower mesosphere, and not in the upper stratosphere. Additional enhancement of GW variance, especially clear in the upper stratosphere, was also found during 2001–2002 and winter 2005–2006.

A high-performance Raman lidar operating in the UV portion of the spectrum has been used to acquire. for the first time using a single lidar, simultaneous airborne profiles of the water vapor mixing ratio, aerosol backscatter, aerosol extinction, aerosol depolarization and research mode measurements of cloud liquid water, cloud droplet radius, and number density. The Raman Airborne Spectroscopic Lidar (RASL) system Was installed in a Beechcraft King Air B200 aircraft and was flown over the mid-Atlantic United States during July-August 20117 at altitudes ranging between 5 and 8 km. During these flights, despite suboptimal laser performance and subaperture use of the telescc pc, all RASL measurement expectations were met, except that of aerosol extinction. Following the Water Vapor Validation Experiment-Satellite/Sondes (WAVES_2007) field campaign in the summer of 2007, RASL was installed in a mobile trailer for ground-based use during the Measurements of Humidity and Validation Experiment (MOHAVE-II) field campaign held during October 2007 at the Jet Prepulsion Laboratory's Table Mountain Facility in southern California. This ground-based configuration of the lidar hardware is called Atntospheric Lidar for Validation, Interagency Collaboration and Education (ALVICE). During the MOHAVE-II field campaign, during which only nighttime measurements were made, ALVICE demonstrated significant sensitivity to lower-stratospheric water vapor. Numerical simulation and comparisons with a cryogenic frost-point hygrometer are used to demonstrate that a system with the performance characteristics of RASL ALVICE should indeed be able to quantify water vapor well into the lower stratosphere with extended averaging from an elevated location like Table Mountain. The same design considerations that optimize Raman lidar for airborne use on a small research aircraft are, therefore, shown to yield significant dividends in the quantification of lower-stratospheric water vapor. The MOHAVE-II measurements, along with numerical simulation, were used to determine that the likely reason for the suboptimal airborne aerosol extinction performance during the WAVES_2007 campaign was a misaligned interference filter. With full laser power and a properly tuned inter ference filter. RASL is shown to be capable of measuring the main water vapor and aerosol parameters with temporal resolutions of between 2 and 45 s and spatial resolutions ranging from 30 to 330 m from a flight altitude of 8 km with precision of generally less than 10%, providing performance that is competitive with some airborne Differential Absorption Lidar (DIAL) water vapor and High Spectral Resolution Lidar (HSRL) aerosol instruments. The use of diode-pumped laser technology would improve the performance of an airborne Raman lidar and permit additional instrumentation to be carried on board a small research aircraft. The combined airborne and ground-bated measurements presented here demonstrate a level of versatility in Raman lidar that may be impossible to duplicate with any other single lidar technique.

The MOHAVE 2009 campaign took place at the Jet Propulsion Laboratory (JPL) Table Mountain Facility on October 11-27, 2009. This campaign allowed a thorough evaluation of the JPL Raman Lidar measurements throughout the troposphere (ground to 20 km). Simultaneous and ozone measurements from the JPL co-located tropospheric and stratospheric ozone lidars allowed to study the relationship between ozone and water vapor up to 14-15 km at very short time scales.

The gravity wave activities in the stratosphere and mesosphere of subtropics during the sudden stratospheric warming were studied using the temperature profiles measured by the Jet Propulsion Laboratory (JPL) Rayleigh lidar at Mauna Loa Observatory (19.5N, 195.6W), Hawaii, and horizontal wind profiles measured by the MF radar at Kauai (22°N, 200.2°W), Hawaii . We found that the significant enhancement of gravity wave activities was observed before the sudden stratospheric warming in winter 2005/2006, followed by the decrease of activity during and after the warming. The significant change of GW activities during the warming will be discussed together with the ECMWF wind in the stratosphere, MF radar and TIMED/TIDI mean winds in the mesosphere.

The gravity wave activities in the stratosphere and mesosphere of subtropics during the sudden stratospheric warming were studied using the temperature profiles measured by the Jet Propulsion Laboratory (JPL) Rayleigh lidar at Mauna Loa Observatory (19.5N, 195.6W), Hawaii, and horizontal wind profiles measured by the MF radar at Kauai (22°N, 200.2°W), Hawaii . We found that the significant enhancement of gravity wave activities was observed before the sudden stratospheric warming in winter 2005/2006, followed by the decrease of activity during and after the warming. The significant change of GW activities during the warming will be discussed together with the ECMWF wind in the stratosphere, MF radar and TIMED/TIDI mean winds in the mesosphere.

One‐night (28 October 2003) temperature and horizontal wind measurements by a resonance sodium (Na) wind/temperature lidar at Maui (20.7°N, 156.3°W) and temperature measurement by a Rayleigh lidar at Mauna Loa Observatory (MLO, 19.5°N, 155.6°W), Hawaii, were used to study gravity wave (GW) propagation from the lower stratosphere to the lower thermosphere. A dominant wave mode was identified from 35 to 103 km. The wave was partially dissipated and propagating upward with a scale height of temperature amplitude at ∼14 km. A damping layer was present around the stratopause where the wave amplitude was small, which also corresponded to a low static stability layer. The vertical wavelengths were larger in the mesosphere (12–13 km) than in the stratosphere (6–7 km), consistent with the decreasing static stability with altitude. Hodograph analysis of the Na lidar wind data showed that the wave was propagating northward and the horizontal wavelength was 2140 km and intrinsic period was 15 h in the region 84–103 km. The apparent period was ∼6 h and consistent with Doppler shift of the background wind. It is suggested that the convective zone over the equator to the south of Hawaii provided a constant GW source that is responsible for the observed GW throughout the night.