Distribution Of Cloud Cover Research Articles

Florida State University’s Tropical Prediction Model

A description of the Florida State University's Tropical Prediction Model is presented in this paper. The model is designed for studies of weather systems over a limited area. Some of the present ingredients of the model are: (i) quasi-Lagrangian advective scheme; (ii) bulk-aerodynamic formula to specify air-sea interaction; (iii) radiative cooling as a function of evolving temperature, moisture and parameterized cloud cover distributions; (iv) parameterization of deep cumulus convection on the basis of a principle of conservation of moist static energy. Lateral boundary conditions and initialization procedures currently being used are outlined. Case studies showing application are being presented separately. DOI: 10.1111/j.2153-3490.1973.tb00637.x

Visible and Infrared Imagery from Meteorological Satellites

The data from meteorological satellites have provided the research community and the operational user during the past decade with global visible and infrared measurements which have served as valuable inputs for the better understanding of the earth-atmosphere system. Early in the meteorological satellite program, the instrumentation largely consisted of vidicon imaging devices and low spatial resolution scanning radiometers. In contrast, current devices being flown on meteorological spacecraft include high spatial resolution scanning radiometers, spectrometers, and high signal-to-noise ratio imaging systems. This array of instrumentation, flown on twenty-eight spacecraft, has permitted the researcher and operational user to (1) remotely measure surface temperatures, (2) deduce the vertical profiles of temperature, water vapor, and ozone, (3) ascertain atmospheric kinematics from cloud motions, cloud characteristics, and circulation patterns, (4) detect and track cyclones and local storms, (5) calculate the heat balance of the earth-atmosphere system, (6) determine the nature and distribution of cloud cover, and (7) remotely detect natural resource boundaries and characteristics.

Cloud cover statistics and their use in the planning of remote sensing missions

In mission planning for satellite-borne remote sensing experiments thepresence and distribution of cloud cover should be taken into account. What is required is the ability to state the probabilities of specific areas having no cloud cover (clear) either on a given occasion or at different times corresponding to a sequence of satellite passes. This paper describes a preliminary approach to the assembly of a set of basic statistics in the form of a worldwide data bank. It summarizes the manipulations of these statistics to permit their use in generating cloud cover distributions for areas differing in size from that of the data base and in expressing conditional distributions at times and distances other than those tabulated. An example of the application of these statistics to the Gulf Stream region, is provided using a Monte Carlo simulation approach. Graphs for this area are generated relating percent coverage to the probability of that coverage as a function of the number of satellite passes.

The Radiative-Photochemical Response of the Mesosphere to Fluctuations in Radiation

The response of the mesosphere to slow fluctuations in ultraviolet and visible radiation intensity is investigated using the simplified models for photochemistry and radiative transfer developed by Lindzen and Goody (1965). Fluctuations in oxygen's ultraviolet bands, ozone's ultraviolet bands and ozone's visible band are separately considered. It is found that the mesosphere is most sensitive to fluctuations in ozone's ultraviolet bands above 35 km and to fluctuations in oxygen's ultraviolet bands above 30 km. At levels of peak sensitivity, fluctuations of about 12 per cent in either of these bands will give rise to temperature fluctuations of 2 deg K. This appears to rule out minute changes in solar ultraviolet emission as a cause for the ‘26-month’ oscillation in the equatorial mesosphere. It is also found that the mesosphere is quite sensitive to fluctuations in visible light in the region between 20 and 35 km where fluctuations of 3–6 per cent in visible radiation can give rise to fluctuations of 2 deg K in temperature. On the average, about 26 per cent of the visible radiation in the mesosphere is received via reflection from below. Much of the reflection is from clouds and hence, variation in cloud cover forms an effective way of varying visible light in the mesosphere. In this connection it is found that the winter distribution of cloud cover in the subarctic is such as to introduce into the mesosphere a temperature disturbance whose amplitude and spatial distribution are such as to be able to trigger a sudden warming of the Northern Hemisphere winter variety.

Cloud Heights and Nighttime Cloud Cover from TIROS Radiation Data

Abstract Radiation data obtained from TIROS III have been analyzed, separately for day and for night, for the period July through September 1961. The global distribution of the average effective temperatures measured by the 8–12 μ channel of the satellite radiometer shows a close correlation with the cloud cover data. An estimate of the latitudinal distribution of cloud heights has been obtained using the TIROS radiation data for daytime and the distribution of cloud cover recently obtained from the TIROS photographs. Combining these values of the cloud heights with the nighttime radiation data determines the latitudinal distribution of nighttime cloud cover. The results indicate that in the Southern Hemisphere the percentage cloudiness at night is considerably higher than in the day, while in the case of the Northern Hemisphere the cloudiness appears to decrease at night.

Latitudinal Distribution of Cloud Cover from Tiros III Photographs

Television pictures from the Tiros III satellite have been analyzed on a computer to give the latitudinal distribution of cloud cover during the summer of 1961. The results, which will be useful in studying the heat balance of the atmosphere and in the determination of vertical motion, show good agreement with the longterm average cloudiness derived from data accumulated during 50 years of ground observations.