摘要:

We discuss the atmospheric variability and instrumental uncertainties which limit the determination of the atmospheric lifetime of fluorocarbons. These factors produce substantial uncertainties in the current estimates of fluorocarbon lifetimes. However, because fluorocarbon production has remained relatively constant over the past few years, the atmospheric lifetime may now be determined with considerably improved accuracy. Analysis of the data by trend and total overburden techniques are compared; the trend method is to be preferred after the first year or two because it allows systematic errors to be reduced. The detectability of a sink is illustrated for a network of four stations spaced around the globe at which measurements are made at least daily. We conclude that 5 years of operation of such a network should enable us to establish whether atmospheric lifetimes of 20 years or less exist.

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05493

年代:1978

数据来源: WILEY

摘要:

A large number of electrochemical concentration cell ozonesondes were calibrated in relation to an ultraviolet photometric absorption ozone instrument prior to using the ozonesondes in atmospheric soundings. The two methods of measuring ozone were in reasonable agreement on the average, but there was considerable variation from one ozonesonde to another. Averaging the individual linear regressions gives [O3]ECC= 0 ± 8 nbar + (0.96 ± 0.10)[O3]UV, where uncertainties represent 90% confidence limits. Applying individual calibration corrections to atmospheric sounding data reduced the mean difference between Dobson spectrophotometric measurements of total ozone overburdens and corresponding values obtained from ozonesonde data from −8.5 ± 8.2 to −1.4 ± 7.3% for a series of measurements carried out in 1977. Corresponding uncorrected and corrected differences averaged 3.2 ± 9.7 and 1.9 ± 10.6%, respectively, for soundings carried ou

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05501

年代:1978

数据来源: WILEY

摘要:

This is a preliminary analysis of sea surface temperature records from the North Pacific from July 1976 through June 1977. The observations were made by thermistors mounted on drifting buoys and were reported through a telemetry link in Nimbus 6. Typical time series of sea surface temperatures from the buoys show variability on scales ranging from a few hours to the seasonal march. Most conspicuous in the observations are a diurnal cycle associated with summer months, a 4‐ to 10‐day cycle associated with the passage of fronts during the fall and winter, and the seasonal marches of temperature. For the latter case a widespread event is responsible for most of the winter cooling. The warming cycle resembles more the classic sinusoidal march of temperatures. The large thermal anomaly present in the North Pacific during this period is clearly revea

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05505

年代:1978

数据来源: WILEY

摘要:

Methods for inferring absolute velocity from hydrographic observations recently advanced by Stommel and Schott and by Wunsch are compared and found to be based on equivalent dynamical sophistication. The differences in the methods are shown to result from differing assumptions about the scales of the quasi‐steady large‐scale signal and the variability or noise. An objective method of accounting for the noise is advan

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05507

年代:1978

数据来源: WILEY

摘要:

The characteristics of the Butterworth low‐pass filter are well known in electrical engineering. Here we discuss its use for oceanographic records and compare its characteristics with other low‐pass filters now in use: the cosine‐Lanczos filter, the Gaussian filter, and the ideal filter. The Butterworth filter is recursive, i.e., past values of the output are used as input, so a phase shift is introduced unless the data are filtered forward and backward through the same filter. When this is done, the filtered signal differs only slightly from that of other low‐pass filters. Because the Butterworth filter uses fewer multiplicative constants for the same effect, there is a reduction in computer time over other low‐pass filters; the difference becomes more pronounced as more data points

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05510

年代:1978

数据来源: WILEY

摘要:

A series of high vertical resolution profiling current meter (PCM) relative profiles was obtained in the Indian Ocean during May–June 1976, along with a series of White Horse (WH) profiles. We present results of a comparison between PCM and WH profiles from stations at 53°E on the equator and at 0°45′N, north of the Seychelles. Estimated rms differences of velocity components obtained by these two techniques range from ±5 to ±10 cm/s. The larger value coincides with periods when vertical structure with large amplitudes (∼20 cm/s) and short vertical scales (∼ 100 m or less) was detected

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05515

年代:1978

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05523

年代:1978

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JC083iC11p05524

年代:1978

数据来源: WILEY