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Tropical water vapour volume mixing ratio (WVMR) data for October 2004–September 2015 obtained from the Microwave Limb Sounder are used to study its long-term variabilities and tendencies in the height region 12.1–0.002 hPa. Above 0.01 hPa, the WVMR shows minimum March–May and September–November (∼0.7–0.8 ppmv) and maximum during June–August. It shows a large interannual variability at 31–64 km. The results from multivariate regression analysis show an increasing trend with maximum value of ∼0.045 ppmv/yr at 1.21–0.41 hPa. It shows a significant negative solar cycle response at mesospheric heights.

Aims. We study the seasonal evolution of Titan’s lower stratosphere (around 15 mbar) in order to better understand the atmospheric dynamics and chemistry in this part of the atmosphere. Methods. We analysed Cassini/CIRS far-IR observations from 2006 to 2016 in order to measure the seasonal variations of three photochemical by-products: C4H2, C3H4, and C2N2. Results. We show that the abundances of these three gases have evolved significantly at northern and southern high latitudes since 2006. We measure a sudden and steep increase of the volume mixing ratios of C4H2, C3H4, and C2N2 at the south pole from 2012 to 2013, whereas the abundances of these gases remained approximately constant at the north pole over the same period. At northern mid-latitudes, C2N2 and C4H2 abundances decrease after 2012 while C3H4 abundances stay constant. The comparison of these volume mixing ratio variations with the predictions of photochemical and dynamical models provides constraints on the seasonal evolution of atmospheric circulation and chemical processes at play.

There is an unusual decrease of semi-diurnal tidal amplitude in zonal wind at 88 km over Tirunelveli (8.7°N, 77.8°E) prior to the onset of a minor warming event of 2011. During that time, there is a sudden decrease of TIMED-SABER observed ozone volume mixing ratio (VMR) at equator and 60°N. It is suggested that the enhanced planetary wave activity prior to the occurrence of SSW increases the strength of the Brewer–Dobson circulation, which transports stratospheric ozone, the solar insolation absorption of which mainly generates semi-diurnal tide, to high-latitude lower stratosphere and as expected, ozone VMR at 70°N increases in the lower stratosphere.

Research and characterizing the ozone profiles and Ozone Depleting Substances (ODS) in Indonesia is a satellite data-based research activities. The aim of the study was to obtain the characteristics of ozone in Indonesia as well as the contribution of ODS to the variability of ozone. By performing a data inventory based on satellite data, analyze the pattern of annual, seasonal and perform linkage analysis of the contribution of ODS changes to the conditions of ozone. Daily data of vertical profiles of ozone and in the form of volume mixing ratio (vmr) with format HDF (Hierarchical Data Format) is extracted to the territory of Indonesia to take parameters as latitude, longitude, and concentration. Then converted to Excel format with the help of data processing software of MATLAB. Results obtained in the form of ozone characteristics in Indonesia, the percentage of contribution to the variability of ozone also contribution to the variability of ozone in Indonesia in several levels of height. By using Microwave Limb Sounders (MLS) AURA satellite data in the period of 2005 to 2013 characteristics of monthly vertical profiles of ozone in Indonesia has been obtained. The ODS studied were ClO and BrO. Peak of vertical profiles of ozone occurs at a pressure of 10 hPa or altitude of 25.9 km. ClO peak occurs at a pressure of 2.1 hPa or altitude of 30.6 km and BrO reached the peak at 14 hPa or altitude of 24.5 km. When ClO and BrO reach a maximum concentration at stratosphere then ozone molecules is potentially damaging or decrease in the stratosphere. Temporal variations of ozone showed decrease when ODS concentrations increased (particularly ClO and BrO). Linear regression of ozone with ozone showed a negative correlation coefficient which indicates there is a strong relationship between ozone concentrations decline in pressure of 14 hPa when BrO reach the maximum. Likewise for ClO which also showed a negative correlation with the decrease in ozone concentration. ClO contribution to the decreasing of ozone in Indonesia was marked by every addition of 0.01 ppb ClO will reduce ozone of 0.00583 ppm (5.83 ppb). While any increase of 0.01 ppb of BrO will decrease 0.03 ppb of ozone.

We reexamine the “stratospheric fountain” hypothesis by comparing estimates of the annually and zonally averaged volume mixing ratio (vmr) of water vapor entering the stratosphere to annually and zonally averaged estimates of the saturation vmr of the tropical tropopause-region. We find that the vmr of water vapor entering the stratosphere (3.8±0.3 ppmv) agrees well with the saturation vmr of the tropical tropopause-region (4.0±0.8 ppmv). Consequently, our analysis provides no support for the “stratospheric fountain” hypothesis, which required troposphere-to-stratosphere transport to occur preferentially in regions where the tropical tropopause is colder than average.

We have used a one-dimensional photochemical model to investigate the potential role of OBrO in stratospheric photochemistry. The OBrO lifetime against photolysis is likely to be very short (around a few s) which prevents any appreciable concentration during sunlit hours. This rapid photolysis also prevents the gas-phase production of significant OBrO in the model during twilight, as possible precursors (e.g. BrO) are converted to their nighttime reservoirs. Using a range of possible gas-phase production reactions, the maximum (nighttime) OBrO volume mixing ratio produced in the model in the lower stratosphere is around 0.01 × 10−12 (0.01 pptv). These model results contradict recent tentative nighttime balloon observations of large OBrO [Renard et al., 1997, 1998]. We have used our model results to put constraints on the rates of gas-phase and heterogeneous reactions that would be necessary to produce appreciable amounts of OBrO in the stratosphere. These constraints show that if OBrO is indeed present in the nighttime stratosphere at the pptv level, our current understanding of atmospheric bromine chemistry is severely flawed.

Spectroscopic observations of Jupiter at thermal–infrared wavelengths were performed on November 8–9 and December 14, 1994, 16 and 21 weeks after the fragments of comet Shoemaker–Levy 9 collided with Jupiter. Residual stratospheric ammonia was searched for in emission at 930.76 cm−1over the longitudes corresponding to the remnants of the D/G/R/S impact sites. We believe a small amount of ammonia may have been detected in November, but report an upper limit for both dates. The constant volume mixing ratio for pressure levels less than 10 mbar that best fits the observation on November 8 is no more than 3.6 ± 2.4 × 10−10. This upper limit decreased to ≤2.3 ± 3.0 × 10−10on December 14. These values are equivalent to upper limits of 1.9 ± 1.2 × 10−10on November 8 and ≤1.2 ± 1.5 × 10−10on December 14 if we adopt a constant volume mixing ratio above a base at 100 mbar. We also searched, without success, for stratospheric ammonia on November 9 over the K/W and L impact site remnants. Our upper limits place stronger constraints on the stratospheric ammonia lifetimes and photochemical depletion models.

The GRILLE infrared spectrometer was part of the shuttle pay load during the first ATLAS mission in March-April 1992. This experiment measured the vertical distribution of several important minor constituents in the middle to high atmosphere by solar occultation mid-infrared absorption spectroscopy. Among the molecules observed is the stratospheric chlorine reservoir species HCl. This paper discusses the vertical profiles measured, including their validation with respect to correlative measurements from ATMOS on board the same mission and from HALOE on board UARS. The most important conclusion drawn from the measured HCl volume mixing ratio of (3.6±0.2) ppbv above 50 km presently measured by GRILLE in comparison with published ATMOS data from 1985 is that the actual GRILLE data confirm the increase of the upper stratospheric total chlorine loading by about 40% with respect to 1985, as reported and/or predicted earlier.

Vertical distributions of ClO, HCl, N 2 O, and O 3 have been retrieved from airborne observations of pressure-broadened emission spectra in the frequency range of 620 to 690 GHz. Observations were made in February 1994 in the Arctic stratosphere above northern Europe with the Airborne Submillimeter SIS Radiometer (ASUR) during the Second European Stratospheric Arctic and Mid-latitude Experiment (SESAME) 1 campaign. ASUR is the first airborne submillimeter experiment to employ the new superconductor-insulator-superconductor (SIS) receiver technology for stratospheric ozone research. Owing to meteorological conditions, all observations were made outside the polar vortex. The retrieved volume mixing ratio (VMR) profiles show a good agreement with observations made by the submillimeter limb sounder (SLS) operated by the Jet Propulsion Laboratory (JPL) (Pasadena) and the Kern Forschungs Anlage (KFA) (Julich). A comparison between retrieved VMR profiles and profiles obtained from the SLIMCAT three-dimensional stratospheric chemistry model also shows a good agreement. Two ClO emission lines, at 649 and 686 GHz, respectively, are shown to be equally adequate lines for observation purposes. An anticorrelation has been found between the N 2 O and HCl VMR values, and also between the N 2 O and ClO VMR values. The correlations between N 2 O and HCl do not show the relatively low HCl VMR values correlated to relatively low N 2 O values as shown by Webster et al. [1994].

We compare volume mixing ratio profiles of N2O, CFC-11, CFC-12, CCl4, SF6, and HCl in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov. 1994. Good agreement is found between ATMOS and in situ correlations of [CFC-11], [CFC-12], and [SF6] with [N2O]. ATMOS measurements of [CCl4] are 15% high compared to ER-2 data, but agree within the systematic uncertainties. ATMOS observations of [HCl] vs [N2O] are within approximately 10% of ER-2 data for [HCl] > 1 ppbv, but exceed in situ measurements by larger fractional amounts for smaller [HCl]. ATMOS measurements of [ClONO2] agree well with values inferred from in situ observations of [ClO], [NO], and [O3]. The sum of [HCl] and [ClONO2] observed by ATMOS, supplemented by a minor contribution from [ClO] estimated with a photochemical model, is consistent with the levels of inorganic chlorine inferred from in situ measurements of chlorine source gases.

We compare volume mixing ratio profiles of N2O, O3, NO(y) H2O, CH4, and CO in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov 1994. ATMOS and ER-2 observations of [N2O] show good agreement, as do measured correlations of [O3], [NO(y)], [H2O], and [CH4] with [N2O]. Thus a consistent measure of the hydrogen (H2O, CH4) content of the lower stratosphere is provided by the two platforms. The similarity of [NO(y)] determined by detection of individual species by ATMOS and the total [NO(y)] measurement on the ER-2 provides strong corroboration for the accuracy of both techniques. A 25% discrepancy in lower stratospheric [CO] observed by ATMOS and the ER-2 remains unexplained. Otherwise, the agreement for measurements of long-lived tracers demonstrates the ability to combine ATMOS data with in situ observations for quantifying atmospheric transport.

Balloon-borne infrared sunset solar spectra in the 780 cm−1 region have been used to derive upper limits for the amount of ClONO2 in the stratosphere. These upper limits for the volume mixing ratio are 4 × 10−11 to 2 × 100−9 between 15 and 30 km with an error factor of 2. These values only show that the postulate that ClONO2 is a temporary reservoir for ClO and NO2 cannot be ruled out.

The simultaneous measurement of the 1-0 bands of HCl and HF has been achieved from near-infrared solar absorption spectra obtained during a balloon flight near Fairbanks, Alaska (65°N, 148°W) in the evening of May 22, 1976. Several lines from each band have been measured to provide volume mixing ratio profiles for both constituents from 15 to 30 km. The HCl profile is consistent with the results of other workers, however the HF profile shows a substantially larger concentration than a recent determination.

An overview is given of the positive ion composition measurements performed with balloon-borne ion mass spectrometers in the Earth's atmosphere between 20 and 45 km. In particular, attention is paid to the derivation of the acetonitrile volume mixing ratio profile. The results are compared with model calculations, data obtained with airplane-borne instruments, and ground-level samplings. The consistency of the present picture is verified. The comparison with results of recent laboratory experiments show that electric field-induced collisional dissociation occurs in balloon-borne ion mass spectrometers. Probably, this is one of the major causes for the observed discrepancies between the data of airplane- and balloon-borne instruments.

Middle and upper stratospheric HCN has been measured using ground-based mm-wave emission spectroscopy during a series of observations made in Mauna Kea, HI, in June 1986. A volume mixing ratio of 190 + or - 40 pptv at about 40 km, and a decrease of concentration with altitude that is considerably slower than that predicted by current models are found. This could be an indication of an atmospheric source of HCN as yet unidentified.

In July 1974 an NO/O3 chemiluminescent instrument was used to obtain measurements of NO in the stratosphere during two balloon flights launched from Churchill (59°N, 95°W). On the first flight, an altitude profile was obtained in which the NO volume mixing ratio was observed to increase from 0.3 to 2.7 ppbv between 19 and 29.5 km. On the second flight, the mixing ratio was observed to increase from 0.25 to 2.7 ppbv between 19 and 29 km and to remain almost constant at about 2.7 ppbv from 29 to 34.5 km. On this flight, the sunset decay of NO was also obtained while the payload was at a constant float altitude of 34.5 km. These decay measurements are compared satisfactorily with the results obtained from a time dependent stratospheric model.

Simultaneous measurements of NO and NO 2 in the stratosphere leading to an NO x determination have been performed by means of i.r. absorption spectrometry using the Sun as a source in the 5·2 μm band of NO and in the 6·2 μm band of NO 2 . The observed abundance of NO P peaks at 26 km where it is equal to (4·2 ± 1) × 10 9 cm −3 . The volume mixing ratio of NO p was observed to vary from 1·3 × 10 −9 at 20 km to 1·3 × 10 −8 at 34 km.

Vertical profiles of the CH4 mixing ratio in the troposphere and stratosphere were obtained by collecting air samples and analyzing their CH4 concentrations by gas chromatography. Two sets of tropospheric profiles, each covering a full year, have been measured; one over the Pacific 200 km offshore from Santa Barbara, California, and one over Scottsbluff, Nebraska. Although some of the individual profiles showed large fluctuations with time and space, a systematic seasonal variation of tropospheric CH4 concentration could not be established. On a 1-year average, CH4 has a nearly uniform distribution in the troposphere, with an average volume mixing ratio of 1.41 ppmv. The only systematic gradient in the troposphere was observed for the Scottsbluff profiles which showed a decrease in the CH4 mixing ratio close to the ground. In contrast, the stratospheric CH4 profiles showed a systematic decrease with altitude, with a steeper gradient directly above the tropopause. The gradient appears to be weaker at higher altitudes. At 50 km the CH4 mixing ratio has dropped to 0.25 ppmv.

Vertical profiles of the stratospheric CCl4, CH3C1, CH3CC1, C2F2C13 mixing ratios derived from two balloon flights over Southern France (44° N) in 1982 and 1983 are presented. A total of 26 air samples were collected in situ by a newly developed balloon-borne cryogenic sampler. The samples were analysed in the laboratory within four weeks after the flight employing two different analytical techniques: gas chromatography and a gas chromatograph/mass spectrometer combination. The observed mixing ratios are well in the range of previous determinations of these species in the stratosphere. Above about 30 km CC14 and CH3CC13 mixing ratios are below the analytical detection limits of both techniques. A comparison with 1-D model calculations shows that for all species the observations are lower than the theoretical profiles.

Spectral line emission at 183 GHz (1.64-mm wavelength) by upper atmospheric H 2 O was measured on the NASA Convair-990 during the Interhemispheric Survey in October and November 1976. The measurements indicate a water vapor volume mixing ratio of approximately 5 × 10 −6 in the upper stratosphere/lower mesosphere and suggest an increase in upper stratospheric H 2 O from subtropical to subpolar latitudes.

Three millimeter-wavelength transitions of ClO were searched for in the stratospheric emission spectrum during May-August 1977 using aircraft-based instruments. The measurements indicate that if stratospheric ClO has a vertical distribution of the form predicted by present photochemical models, then the ClO volume mixing ratio at the profile peak did not exceed 10 to the -9th at the time and place of the measurements. The observed spectra suggest the presence of ClO in the stratosphere but do not provide a definitive detection.

The altitude distribution of nitric oxide was measured during three balloon flights in August 1976 and 1978. Median values of the volume mixing ratio at 18, 24, 30, and 34 km were 0.4, 1.4, 6.5, and 13 ppb, respectively. The data are discussed in relation to an average profile of nitrogen dioxide measured for this season and latitude and in relation to current one-dimensional models of the stratosphere.

The atmospheric distribution of CH 4 is rather uniform zonally and vertically but exhibits a slight gradient with latitude in the troposphere; in the stratosphere it shows a definite decrease with altitude. The average volume mixing ratio in the troposphere is 1.4 ppm which corresponds to a total amount of 4 × 10 15 g of CH 4 present in the atmosphere. Most is of recent biologic origin. C 14 analyses show that no more than 20% is released by fossil sources. The various ecosystems producing CH 4 are discussed and the total annual production is estimated to lie between 5.5 × 10 14 g/yr and 11 × 10 14 g/yr. The corresponding turnover times for atmospheric CH4 range from 4 to 7 yr. The destruction of CH 4 takes place mainly in the troposphere, most probably through the reaction CH 4 + OH ? CH 3 + H 2 O. About 10% of the CH 4 is destroyed in the stratosphere. The CH 4 cycle is strongly coupled to the H 2 and CO cycles and contributes also on the order of 1% to the atmospheric carbon cycle. DOI: 10.1111/j.2153-3490.1974.tb01952.x