An improved rocket ozonesonde (ROCOZ‐A): 3. Northern mid‐latitude ozone measurements from 1983 to 1985

A series of coordinated atmospheric ozone profile measurements was made during October and November 1988. The instruments making observations and their locations were as follows. The Jet Propulsion Laboratory (JPL) and Goddard Space Flight Center differential absorption lidar systems were located at the JPL‐Table Mountain Facility 34.4°N, 117.7°W. The electrochemical concentration cell balloon sondes and the rocket ozonesondes were both launched from Point Mugu Naval Air Station at 34.2°N, 119.2°W. Stratospheric Aerosol and Gas Experiment (SAGE II) satellite measurements were at various latitudes and longitudes but only measurements made within 1000 km of both of the above sites were considered for this intercomparison study. It was found that at least for the time of year of the study, SAGE II measurements agreed only when they were made much closer than 1000 km (<500 km) from the other sites, and this is explained in terms of the large latitudinal gradient observed in the ozone concentration profile. Agreement to 5% was seen between the instruments, over the altitude range from 20 to 50 km, when the measurements were made close together in both time and space.

Section: Methodsmentioning

confidence: 99%

Comparison of ozone profiles from ground‐based lidar, electrochemical concentration cell balloon sonde, ROCOZ‐A rocket ozonesonde, and Stratospheric Aerosol and Gas Experiment satellite measurements

McDermid¹,

Godin²,

Barnes³

et al. 1990

“…In addition, intercomparison of the OHP and BIS systems, located within a distance of 500 km, with over 66 simultaneous profiles reveals a difference of less than 2øC below 80 km [WMO, 1989]. The datasonde instrument, a mobile system, has been used since about 1968 to validate satellite temperature observations and often in conjunction with rocket ozonesonde as part of satellite and lidar ozone intercomparison campaign programs [e.g., Barnes et al, 1989;and Barnes et al, 1991]. Schmidlin [1981] studied the repeatability and measurement uncertainty of the rocket datasonde.…”

Section: Temperature Profile Comparisonmentioning

confidence: 94%

SAGE II stratospheric density and temperature retrieval experiment

Wang¹,

McCormick²,

Chu³

et al. 1992

This paper describes a stratospheric density and temperature retrieval experiment based on the solar occultation measurement of the Stratospheric Aerosol and Gas Experiment (SAGE II). The entire retrieval analysis involves two inversion steps: the vertical structure inversion, which derives the profile of local atmospheric extinction from SAGE II limb optical depth data, and the species inversion, which inverts the concentration of air molecules, aerosols, ozone, and nitrogen dioxide from the derived atmospheric extinction at five SAGE II short wavelengths (0.385, 0.448, 0.453, 0,525, and 0.600 μm). The inversion schemes for these steps are Twomey's (1975) modification of Chahine's nonlinear inversion algorithm and the Levenberg‐Marquardt nonlinear least squares method, respectively. The derived density profile is then used to infer the temperature distribution, assuming that the atmosphere is in hydrostatic equilibrium and obeys the ideal gas law. The retrieval analysis is illustrated in detail by using a SAGE II measurement event that occurred on September 15, 1987 (43.6°N, 4.1°W). An estimate of the error associated with the retrieved molecular density and temperature profiles based on the propagation of the instrument measurement error, the reference altitude error, and an assigned 10% error to the pressure at the top measurement level is also provided. The temperature profiles retrieved from the SAGE II observations are compared with near‐coincident, in both time and space, French Rayleigh lidar and NASA Wallops Flight Facility rocket datasonde soundings as well as the National Meteorological Center (NMC) data analyses. The results indicate that the mean SAGE II temperature agrees with the mean lidar measurement to within 2°C at altitudes from 30.5 to 52.5 km. The SAGE II and datasonde observations agree to within about 4°C in approximately the same altitude region. The mean temperature difference between the SAGE II and NMC analyses are, on average, about 1°, 4°, 2°, and 3°C at the standard pressure levels of 10, 5, 2, and 1 mbar, respectively.

“…Estimates of the accuracies and precisions of the measurements from the ROCOZ-A flight series have been documented in the literature. The most complete set of estimates can be found in Tables 8 and 9 of Barnes et al [1989]. These are the same values that are found in the STOIC overview paper [Margitan et al, this issue].…”

Section: Introductionmentioning

confidence: 99%

ROCOZ‐A ozone measurements during the Stratospheric Ozone Intercomparison Campaign (STOIC)

Barnes¹,

Parsons²,

Grothouse³

1995

Self Cite

We present a set of ROCOZ‐A (rocket ozonesonde) ozone measurements during the October/November 1988 (pre‐STOIC) and the July/August 1989 Stratospheric Ozone Intercomparison Campaign (STOIC) in southern California. ROCOZ‐A and its associated electrochemical concentration cell (ECC) ozonesondes participated in the comparisons as established techniques for the validation of lidar and microwave instruments that have been proposed for the Network for the Detection of Stratospheric Change (NDSC). For the proposed network instruments, STOIC has provided a picture of their performance characteristics in 1989 and has given an estimate of their future performance in the NDSC. For ROCOZ‐A, STOIC has added new information on its accuracy and precision. It is this continuing characterization that gives ROCOZ‐A its value in comparisons. The STOIC comparisons show a shift of 5–6% in ROCOZ‐A ozone densities (ROCOZ‐A higher) from October/November 1988 to July/August 1989. This shift has been seen in comparisons with the Stratospheric Aerosol and Gas Experiment II (SAGE II), ECC ozonesondes, and the Jet Propulsion Laboratory (JPL) lidar. The source of this shift has not been determined. Until this new error source is resolved, we recommend that the previously quoted accuracy estimate for ROCOZ‐A ozone measurements be increased from 5–7% to 8–10%. About 2% of the difference between ROCOZ‐A ozone measurements and those from the proposed network instruments in 1989 appears to be due to differences in atmospheric ozone between the two STOIC sites. A correction for these site‐to‐site differences brings the ROCOZ‐A ozone measurements within 10% of all of the other STOIC instruments, and the average agreement (ROCOZ‐A 6% higher) becomes consistent with the historical set of ROCOZ‐A comparisons. The STOIC comparisons have shown structures in stratospheric ozone that cannot be resolved by ROCOZ‐A with its 4‐km vertical resolution. In addition, comparisons with nighttime measurements from the Millitech microwave above 45 km show a divergence from the daytime ROCOZ‐A values that agrees with the general characteristics of the diurnal cycle in upper stratospheric ozone that is predicted by photochemical models. Evidence of this ozone cycle is also seen in ROCOZ‐A comparisons with the SAGE II zonal mean above 45 km but not in comparisons with the nighttime measurements from the JPL lidar. The effects of diurnal ozone change in the upper stratosphere and mesosphere will be an important consideration in future comparisons of NDSC instruments.