VARIATIONS IN PRECIPITABLE WATER CONTENT IN LOWER TROPOSPHERE AT PUNE DURING SUMMER MONSOON

Variation. in Precipitable Water Content (pWC) at Pune (lse32'N. 73·S1'E..ssg m u 1)duri ngIUmmer mon aoon aealOM of 1980 and 1981. have been studied. Spectrum of PWC values in layen 9OQ..650 bPashowed peals at period. 2-3 and '·8 days. The periodicities observed in PWC ~comparable with these observed. in other mckorolOlical parameters.

Characteristics of Surface Temperature and Its Relationship with Meteorological Elements in China in the Last 73 Years

Climate, as the natural environment on which human life depends, is intricately linked to human society. This paper focuses on the characteristics of temperature and its relationship with meteorological elements in China in the last 73 years. The data of this research is from NCEP/NCAR Reanalysis Monthly Means. This study adopts the Empirical Orthogonal Function (EOF) and Singular Value Decomposition (SVD) methods to study the surface temperature characteristics within China, and the synergistic variation between surface temperature and precipitable water content, wind field, and relative humidity in China. The results show that 1980s is a turning point for changes in surface temperature, precipitable water content, wind field, and relative humidity in China. Before 1980s, the temperature in China is low, while after this period, the temperature in China is high and China’s exposure to global warming has increased. Temperature is dominated by negative potential-phase oscillations with relative humidity and wind fields. In the north, temperature and precipitable water content have negative potential-phase oscillations, while temperature and precipitable water content have positive potential-phase oscillations in the south. In the central region of Xinjiang, temperature and precipitable water content have weak negative potential-phase oscillations, while temperature and wind field have positive potential-phase oscillations.

Environments of Formation of Severe Squalls and Tornadoes Causing Large-scale Windthrows in the Forest Zone of European Russia and the Ural

The environments of 53 severe squalls and tornadoes that caused large-scale windthrows in the forest zone of European Russia and the Ural in 1989–2019 are analyzed. The CFSR and ERA-5 reanalyses and sounding data were used to estimate characteristics of the environments including convective instability indices. It was found that the substantial temperature gradient on the atmospheric front (9.6C/500 km on average) and the jet stream presence in the lower or middle troposphere oriented along the frontal zone are important factors to estimate environments of the formation of severe squalls and tornadoes. In most cases, squalls and tornadoes require a combination of high precipitable water content (40 mm on average), moderate or high convective instability (CAPE >1000 J/kg), and moderate or strong wind shear. High precipitable water content and strong convective instability are important for the formation of squalls, while low-level wind shear plays a principal role for the tornado generation.

STUDIES ON THE TOTAL COLUMN ATMOSPHERIC AEROSOL OPTICAL DEPTH, OZONE AND PRECIPITABLE WATER CONTENT IN THE TROPICS: A CASE STUDY OF MALAYSIA

A Multifilter Rotating Shadowband Radiometer has been used to monitor the directly transmitted solar irradiance at six wavelength regions (413.9 nm, 494.6 nm, 612.7 nm, 670.8 nm, 868.0 nm and 939.1 nm) for three clear stable days at Bangi. Extensive observations of the columnar aerosol optical depth (AOD), total column ozone (TCO) and precipitable water content (PWC) have been carried out using this instrument. The result shows that the maximum optical depth of aerosol at the shorter wavelength, especially on 24th February 2002 with mean value of 0.254 (24th February 2002), 0.095 (25th February 2002), and 0.072 (26th February 2002) while the ozone optical depth shows the mean value 0.0153 on 24th February 2002, 0.0174 on 25thFebruary 2002 and 0.0175 on 26th February 2002 with the avarage absorption coefficient (a), 0.2 (24th and 26th February 2002) and 0.1 (25th February 2002). The mean value of water vapor content shows that  = 0.356 cm and k = 0.301 cm for wavelength 939.1 nm. From the aerosol optical depth, it shows the existence of smoke type of aerosol on February, 24th to 25th 2002 with Ångström coefficient, , is 1.534 and 1.5513, respectively, and sea water vapor is 0.9889 on 26thFebruary 2002. From the Ångström coefficient, it shows that atmosphere layer of Bangi at that moment is similar to U.S. Standard Atmosphere, with maximum spectral irradiance on black body temperature is 5860 oK.