摘要:

We present a photochemical theory for tropospheric ozone in which the methane oxidation chain constitutes a large local source. This source produces about 1012odd oxygen molecules cm−2sec−1and implies a photochemical lifetime for ozone of about 1 day, much shorter than characteristic mixing times. The photochemical model reproduces the altitude and seasonal dependence of ozone at 30°N. It also gives qualitative agreement with observed day‐to‐day variations of the ozone

ISSN:0148-0227    

DOI:10.1029/JC078i036p08751

年代:1973

数据来源: WILEY

摘要:

The results of observing the radiation from lightning discharge processes indicated that major radio frequency electrical activity was associated with the tornado‐producing severe storms that struck Oklahoma City during this period. Rates of occurrence of atmospherics at frequencies from 10 kHz to above 3 MHz were observed by using short time constant circuits to preserve the burst nature of the received impulse signals. It is suggested that the parameter most indicative of tornadic activity is the number of bursts of high atmospherics rates at frequencies above about 1 MH

ISSN:0148-0227    

DOI:10.1029/JC078i036p08761

年代:1973

数据来源: WILEY

摘要:

Instrumental neutron activation measurements of Cl and Na in aerosols collected by Andersen cascade impactors from Puerto Rico and the San Francisco Bay area were used to calculate Cl loss from the total aerosol mass and loss as a function of particle size. Calculated Cl losses from Puerto Rican samples ranged from 0.18 to 0.27 μg/m3, representing a 7–25% loss of Cl ascribed to the marine aerosol component. The Cl losses for the bay area marine aerosol ranged from 0.24 to 2.78 μg/m3, or from 6% to nearly 90% of the total particulate marine Cl. In all samples, increasing loss of Cl with decreasing particle size was observed. A linear correlation exists between measured gaseous NO2concentrations and total Cl loss in the bay area samples, indicating a 0.06 μmole/m3Cl loss per μmole/m3NO2. This suggests that the Cl loss is controlled by the attachment of HNO3vapor to the sea‐salt droplets, which lowers thepH, causing the release of HCl to the atmosphere. The size dependency of Cl loss could thus be explained by a size‐dependent gain of H+resulting from the accretion of HNO3vapor on the marine aerosol. A diffusion model based on the accumulation of HNO3necessary to balance the loss of Cl as HCl yields an average time for completion of gas‐particle reactions of 19 min, which is in agreement with previous studies; however, the Cl/Na ratio variation with particle size suggests that chemical equilibrium is not reached. Background levels of gaseous NO2and SO2may account for the narrow range of Cl loss observed in the less polluted Puerto Rican

ISSN:0148-0227    

DOI:10.1029/JC078i036p08778

年代:1973

数据来源: WILEY

摘要:

The Ocean Weather ShipWeather Adviser, underway from the United Kingdom to assume her station at position J (near 53°N, 18°W) on the North Atlantic, encountered very heavy seas over a 5‐day period from March 15, 0900 GMT, to March 19, 2100 GMT, 1968. The ship measured the sea state during this stormy period with a shipborne wave recorder at 3‐hour intervals. From these wave records‐the wave energy spectra are computed and are represented in tabular form. Also, selected spectra from these tables are graphically represented. Two peak energy values calculated from wave records taken on March 17, 0300 and 0900 GMT, were found to occur between the wave periods of 15 and 16.5 sec. Wave heights measured from the above two wave records reached maximums between 60 and

ISSN:0148-0227    

DOI:10.1029/JC078i036p08793

年代:1973

数据来源: WILEY

摘要:

A numerical model is presented that permits the simulation of stratified fluid phenomena in which gravitationally unstable regions are present. The influence of subgrid scale turbulence generation due to convective instability is parameterized by relating eddy viscosity coefficients to the local Rayleigh number in unstable regions. The model is used to study three different laboratory scale flow problems involving gravity wave generation, wave breaking, and penetrative convection. The numerical solutions show good agreement with available experimental and analytic results as well as with a numerical solution obtained by other investigators.

ISSN:0148-0227    

DOI:10.1029/JC078i036p08808

年代:1973

数据来源: WILEY

摘要:

Surface and subsurface samples of seawater collected in the Atlantic, Arctic, Indian, Pacific, and Antarctic oceans have been analyzed for228Ra. The results agree with those obtained by Moore (1969) and show that near‐shore surface waters normally contain much higher228Ra concentrations than surface waters collected in the open sea, that surface waters normally contain much higher228Ra concentrations than intermediate and deep waters, but that nearbottom waters are somewhat enriched in228Ra. Surface waters of the North Atlantic and Indian oceans contain significantly higher concentrations of228Ra than those of the Pacific and Antarctic oceans. Vertical profiles of228Ra activities have been used to calculate values of the constant for vertical eddy diffusionKzof about 0.3 cm2/sec in the Arctic Ocean in the zone between the cold water mass that originates in the Bering Sea and the underlying warmer but more saline water mass that originates in the Atlantic. Values ofKzof about 0.5 to about 7 cm2/sec have been calculated for the upper 200 meters of the Atlantic and Pacific and of about 5–100 cm2/sec for the bottom water masses of the Atlantic and Pacific. The. meridional gradient of228Ra in the surface waters south of Australia and New Zealand has been used to calculate a value of the constant for horizontal eddy diffusion perpendicular to the wind‐driven circulationKYof about 107–108

ISSN:0148-0227    

DOI:10.1029/JC078i036p08827

年代:1973

数据来源: WILEY

摘要:

An independently developed tree ring chronology for bristlecone pine in the White Mountains, California, provides a basis for testing the accuracy of dendrochronological calibration of the radiocarbon time scale. Several lines of evidence show that the growth rings in this species are true annual rings. Internal evidence and cross‐chronology comparison indicate that there is no error in calendar dates assigned to wood specimens for comparative radiocarbon analysis, at least back to 3535 B.

ISSN:0148-0227    

DOI:10.1029/JC078i036p08849

年代:1973

数据来源: WILEY

摘要:

The rotational lines of the first overtone sequence of the hydroxyl rotation‐vibration infrared night airglow bands have been observed from the ground with good resolution both temporally and spectrally. This was achieved with a newly developed wide‐angle prism interferometer spectrometer with cold optics and a thermal‐background‐limited detector. The detailed rotational structures of the (3, 1), (4, 2), (5, 3), and (6, 4) bands were observed with only a 10‐sec scan time through the atmospheric window between 5400 and 6900 cm−1(1.85–1.45 μm). The computed rotational temperature for the (4, 2) band was 225°K for a measurement taken at Poker Flat, Alaska, at 1037 UT on

ISSN:0148-0227    

DOI:10.1029/JC078i036p08859

年代:1973

数据来源: WILEY

摘要:

In an attempt to reduce the complications present in previous electrofreezing experiments, supercooled waterdrops about 3 mm in diameter were suspended aerodynamically in a vertical wind tunnel at temperatures of between −8° and −15°C. Drops were stressed by the application of a steady uniform vertical electric field of magnitude up to and including that causing instability. The collision of supercooled drops, charged and uncharged, with and without external fields was also studied, as was the effect of ‘new’ and ‘aged’ corona products from a metal point at high potential. In no case was an increase in freezing probability observed. For our experimental conditions, in which spurious effects are eliminated, electrofreezing d

ISSN:0148-0227    

DOI:10.1029/JC078i036p08864

年代:1973

数据来源: WILEY

摘要:

Variations of I/Na, Br/Na, and Br/Cl ion ratios with particle size in Puerto Rican marine aerosols suggest behavior of I and Br in agreement with the results of previous studies, although Cl losses are shown to be a significant factor in modifying ion ratios, especially in the submicron particle range.

ISSN:0148-0227    

DOI:10.1029/JC078i036p08867

年代:1973

数据来源: WILEY