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Sigmund Fritz

Abstract

Mean monthly 700 mb height data are analyzed in relation to Pacific Ocean sea-surface temperatures (SST). Instead of treating the winter season as a unit, the data are analyzed separately for December, January and February; some results for November are also included. The associated pattern of the atmospheric circulation is most pronounced in January and February, especially over the Pacific. This indicates that time intervals of one month, and even shorter ones, are long enough to reveal the atmospheric relation to the sea-surface temperature. Moreover, an average of 700 mb data over the Pacific for January and February, would probably show a greater correlation with SST than the “winter” average which commonly includes December. The differences between December and February observations are discussed with the aid of the theoretical model of Hoskins and Karoly (1981).

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SIGMUND FRITZ

Abstract

When air stagnates in dark polar regions, an inversion forms. The change of the inversion magnitude is studied under the assumption that the snow surface radiates about as much energy as it receives from the atmosphere. It turns out that the inversion magnitude may either decrease or increase as the surface temperature falls, depending on the rate of change of atmospheric “emissivity” with air temperature.

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Sigmund Fritz

Abstract

The precipitation over northern Honduras in December was significantly correlated with 700 mb heights over Valencia, Ireland. (Measurements at Valencia were used to represent a more accurate indicator of the variations in the Icelandic Low than interpolated analyses in the Low over the Atlantic Ocean.) This relationship was suggested by a comparison between observed and theoretical “wave-trains” in the 700 mb height field. The observed 700 mb height wave train over the Atlantic was related to anomalies in the sea-surface temperature (SST) over the tropical Pacific Ocean; therefore, the northern Honduran rainfall was also significantly correlated with the tropical Pacific SST.

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Sigmund Fritz

Abstract

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Sigmund Fritz

Abstract

TIROS II measured the emission from the planet Earth in the atmospheric water-vapor window near 10 microns. During carefully selected times, when no clouds were present near sunrise or near noon, the measurements served to estimate the change in temperature of the ground. Under these conditions, although the change in transmittance of the atmosphere can be neglected for the purpose of computing the ground temperature change, the transmittance through the atmosphere must still be evaluated.

During cloudless sky conditions over Wisconsin on 23 November 1960, the change in ground temperature from sunrise to noon was about 24C as estimated from satellite measurements. The change in shelter air temperature was less than 15C over the same time interval.

In overcast areas, the movement and development of the clouds determine the variation of the energy measured by the satellite.

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Sigmund Fritz

Measurements of the upward and downward components of solar radiation were measured from a B-29 airplane on March 22, 1947. From these the albedo of the ground has been calculated. In the center of the country along the 39th parallel of latitude, the albedo of the ground, except when covered in part by snow, was found to be between .07 and .10. As the Western Mountains were approached, the albedo increased to .12. In the mountains, where the color of the terrain varies rapidly, the albedo reached a high value of .23, and averaged about .17. For terrain which was partially snow-covered the highest albedo measured was .29.

Computations were made which showed the absorption of solar radiation to be about .06 ly/min in a unit column reaching from the ground to 10,000 feet which by itself would cause a temperature rise of .05C°/hr. in a cloudless smoky atmosphere.

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Sigmund Fritz

Abstract

The albedo of the whole earth is calculated to be 35 per cent, largely on the basis of Danjon's visual lunar measurements. The calculations also give a value of about 0.50 for the average albedo of clouds, which is in better agreement with measurements than the currently accepted value.

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Sigmund Fritz

Abstract

The mean characteristics of the Aleutian low in January and February are compared. The comparison is made separately for years when the tropical Pacific sea surface temperature (SST) was anomalously high, and when the SST was low. It was found that when the SST was high, and the January sea level pressure (SLP) in the Aleutian low center was less than 990 mb, the center was east of the Dateline in both January and February; the February SLP also tended to be below normal. It is speculated that the characteristics of the Aleutian low in January and February under these conditions may be due to interaction between the influences of precipitation distribution over the tropical Pacific and the large-scale wind flow near the Asian coast.

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Sigmund Fritz

Abstract

Nimbus 3 and 4 satellites carried Satellite Infrared Spectrometers (SIRS-A and SIRS-B, respectively). One of the channels on each spectrometer measured the energy emitted from the stratosphere in a narrow wavelength interval in the middle of the 15-µm CO2 band. The measured radiance changes are indicative of temperature changes in the stratosphere.

In the tropics, the annual and semi-annual march of radiance (or temperature) depends on the variations of solar energy absorbed by ozone and on dynamical influences. The radiance changes produced by solar heating of ozone were computed. To do this the concept of “Newtonian cooling” was also utilized.

The computed solar radiances were then compared with the observed radiances; the difference was attributed to dynamical factors. The observed radiances for SIRS-A had a total annual range which did not exceed 6 mW per (m2 ster cm−1). Moreover, the north-south gradient of radiance was very small and there was a strong tendency for the radiances to have a minimum at the equator during much of the year, especially at the solstices. This produces north-south gradients with opposite signs in the Northern and Southern Hemisphere tropics. By contrast, the solar-induced radiances have large annual amplitudes away from the equator, and would produce large radiance (or temperature) gradients. Also, the solar radiance gradients have the same sign on both sides of the equator, especially during the solstices. This would introduce large wind shears in the vertical, and possibly large horizontal wind shears across the equator.

The observed radiance changes are often a residual between large solar radiance changes and large dynamical temperature changes. Near the equator the solar radiances agreed approximately with the observed radiances in the period April–July–October. But in November–January–March, dynamic factors dominated. At tropical latitudes away from the equator (e.g., at 2OS) dynamic factors almost completely balance the solar radiances in the annual cycle, leaving a small residual annual component in the observed radiances. The semi-annual amplitude at 20S is larger for the observed radiances than for the solar radiances; thus, the observed values are a combination of solar and dynamically induced temperature changes.

The dynamical radiance changes suggest that the air was sinking at 30° latitude in winter and rising there in summer. Also, at the equator, the air was rising in January 1970.

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SIGMUND FRITZ

Abstract

The temperature of the atmosphere cannot be deduced from satellite radiance measurements alone; additional information is required. The additional required information is related to the detailed vertical temperature structure of the atmosphere, which is not supplied by the satellite radiance measurements. To deduce the mean temperature (or corresponding mean radiance) in several layers of the atmosphere, the problem may be divided into two parts. One part depends only on the measured satellite radiances; the second part, which depends on the unknown detailed vertical temperature distribution, may be considered as a correction term. Calculations show the magnitude of the two parts. The two parts seem to be related so that mean temperatures (or radiances) can be computed from satellite data with tolerable accuracy with aid of empirical relationships. Other authors have used various assumptions and statistical relations to cope with the required additional temperature information.

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