scholarly journals Spectral characteristics of the quasi-biennial oscillation of total Ozone

MAUSAM ◽  
2021 ◽  
Vol 50 (2) ◽  
pp. 187-196
Author(s):  
R. P. KANE
Keyword(s):  
Total Ozone ◽  
Cross Correlation ◽  
Spectral Characteristics ◽  
Low Latitude ◽  
Quasi Biennial Oscillation ◽  
Special Analysis ◽  
Cross Correlation Analysis ◽  
North Polar ◽  
Biennial Oscillation ◽  
Prominent Peak

The 12-month running means of the 50 hPa low latitude zonal wind and total ozone values for the latitude zones NP (North Polar), NT (North Temperate), TRO (Tropical), ST (South Temperate), SP (South Polar) were subjected to special analysis, separately over the two successive 18 year intervals, 1958-1975 and 1976-1993. In the interval 1958-1975, the wind had a prominent peak at 2.45 years and two smaller but significant peaks at 1.98 and 3.05 years. For ozone only NP. NT and ST had roughly similar peaks (2.37, 2.41, 2.48 years), while TRO and SP had different peaks (2.27 and 2.12 years). All ozone series had significant peaks at 20-21 months, barely significant in the wind series. Ozone peaks were noticed in the 3-5 years band also. In the interval 1976-1993, the patterns were different. The wind had only one prominent peak at 2.51 years. For ozone, NP, NT, ST had roughly similar peaks (2.41, 2.45, 2.45 years) while TRO. Speed different peaks (2.32 and 2.29 years). All ozone series had significant peaks at 20-22 months and in the 3-5 year band; but these were absent in the wind series. The 3-5 year band probably indicates ENSO effects. A cross-correlation analysis between wind and ozone showed that TRO maxima coincided with westerly wind maxima. while NT, ST and NT, NP were phase shifted by 4 and 6 seasons.

scholarly journals Quasi-biennial and quasi-triennial oscillations in the growth rates of atmospheric chlorofluorocarbons 11 and 12

MAUSAM ◽  
2022 ◽  
Vol 53 (3) ◽  
pp. 349-358
Author(s):  
R. P. KANE
Keyword(s):  
Southern Hemisphere ◽  
Growth Rates ◽  
Southern Oscillation ◽  
Spectral Characteristics ◽  
Linear Increase ◽  
Transport Processes ◽  
Emission Rates ◽  
Low Latitude ◽  
The Difference ◽  
Prominent Peak

The 12-monthly running means of CFC-11 and CFC-12 were examined for 1977-1992. As observed by earlier workers, during 1977-1988, there was a rapid, almost linear increase of these compounds, ~70% in the northern and ~77% in the southern hemisphere. From 1988 up to 1992, growth rates were slower, more so for CFC-11 in the northern hemisphere. Superposed on this pattern were QBO, QTO (Quasi-Biennial and Quasi-Triennial Oscillations). A spectral analysis of the various series indicated the following. The 50 hPa low latitude zonal wind had one prominent QBO peak at 2.58 years and much smaller peaks at 2.00 (QBO) and 5.1 years. The Southern oscillation index represented by (T-D), Tahiti minus Darwin atmospheric pressure, had a prominent peak at 4.1 years and a smaller peak at 2.31 years. CFC-11 had only one significant peak at 3.7 years in the southern hemisphere, roughly similar to the 4.1 year (T-D) peak. CFC-12 had prominent QBO (2.16-2.33 years) in both the hemispheres and a QTO (3.6 years) in the southern hemisphere. For individual locations, CFC-11 showed barely significant QBO in the range (1.95-3.07 years), while CFC 12 showed strong QBO in the range (1.86-2.38 years). The difference in the spectral characteristics of CFC-11 and CFC 12 time series is attributed to differences in their lifetimes (44 and 180 years), source emission rates and transport processes.

Wavelet and cross correlation analysis on some climatology parameters of Nepal

BIBECHANA ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 105-116
Author(s):  
Babu Ram Tiwari ◽  
Jiyao Xu ◽  
Binod Adhikari ◽  
Narayan Prasad Chapagain
Keyword(s):  
Wavelet Transform ◽  
Correlation Analysis ◽  
Cross Correlation ◽  
Spectral Characteristics ◽  
Time Lag ◽  
Rate Of Change ◽  
Policy Implications ◽  
Sunspot Numbers ◽  
Cross Correlation Analysis ◽  
Convective Motions

This study has been performed to understand the relationship between sunspot numbers (SSN) with climatology related parameters like temperature and rainfall from 1901 to 2016. The spectral characteristics of sunspot numbers, temperature and rainfall have been observed using continuous wavelet transform. Cross-correlation analyses were also performed to find any relation among temperature, rainfall, and sunspot numbers. The 9–11 year periodicity of sunspot numbers confirmed by wavelet transform in annual scale. The periodicity of high-frequency signals is identified between 4 to 11 years whereas the low frequencies signal is found throughout the periods of observation for temperature. Similarly, it is clear that there is more concentration of power between 8–16 years for rainfall. Cross-correlation analysis shows that the sunspot numbers is highly correlated with rainfall and temperature (correlation coefficient ~ 0.8054). The time lag relationship resulted in the almost simultaneous linear relationship between the temperature, rainfall, and the SSN tendency. The development of convective motions over the subtropics might be affected by the time rate of change of SSN combined with the surface temperature changes of diverse time scales. The convective motions were mostly controlled by the available amount of water vapor and the stability of the atmosphere that had a strong connection with the heat capacity of the concerned region. To produce more authentic findings for policy implications, further comprehensive and appropriate research can be undertaken and implemented in this very important field. BIBECHANA 18 (2) (2021) 105-115

Has the stratospheric HCl in the Northern Hemisphere been increasing since 2005

2020 ◽  
Author(s):  
Yuanyuan Han ◽  
Wenshou Tian ◽  
Fei Xie
Keyword(s):  
Northern Hemisphere ◽  
Linear Trend ◽  
Polar Vortex ◽  
Joint Effect ◽  
Residual Circulation ◽  
Quasi Biennial Oscillation ◽  
Middle Latitudes ◽  
North Polar ◽  
North Polar Vortex ◽  
Biennial Oscillation

<p>Stratospheric hydrogen chloride (HCl) is the main stratospheric reservoir of chlorine, deriving from the decomposition of chlorine-containing source gases. Its trend has been used as a metrics of ozone depletion or recovery. Using the latest satellite observations, the authors find that a significant increase of Northern Hemisphere stratospheric HCl during 2010–2011 can mislead trends of HCl in recent decades. Agree with previous studies, HCl increased from 2005 to 2011; while when removing the large increase of stratospheric HCl during 2010–2011, the increasing linear trend from 2005 to 2011 becomes weak and insignificant, in addition, the linear trend of Northern Hemisphere stratospheric HCl from 2005 to 2016 also shows weak and insignificant. The significant increase of HCl during 2010–2011 is attributed to a super strong north polar vortex and a reduced residual circulation during 2010–2011, which slowed down the transport of HCl from the low–mid latitudes to the high latitudes, leading to accumulation of HCl in the middle latitudes of the stratosphere during 2010–2011. Further analysis suggests that the strong polar vortex and the reduced residual circulation were caused by the joint effect of a La Niña event and the west phase of the quasi-biennial oscillation.</p>

scholarly journals Modes of zonal mean temperature variability 20–100 km from the TIMED/SABER observations

2014 ◽  
Vol 32 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Y. Jiang ◽  
Z. Sheng ◽  
H. Q. Shi
Keyword(s):  
Empirical Orthogonal Functions ◽  
Low Latitude ◽  
Orthogonal Functions ◽  
Quasi Biennial Oscillation ◽  
The North ◽  
Broadband Emission ◽  
Mesospheric Temperature ◽  
Mean Temperature ◽  
Temperature Inversions ◽  
Biennial Oscillation

Abstract. In this study we investigate the spatial variabilities of the zonal mean temperature (20–100 km) from the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics)/SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) satellite using the empirical orthogonal functions (EOFs). After removing the climatological annual mean, the first three EOFs are able to explain 87.0% of temperature variabilities. The primary EOF represents 74.1% of total anomalies and is dominated by the north–south contrast. Patterns in the second and third EOFs are related to the semiannual oscillations (SAO) and mesospheric temperature inversions (MTI), respectively. The quasi-biennial oscillation (QBO) component is also decomposed into the seventh EOF with contributions of 1.2%. Last, we use the first three modes and annual mean temperature to reconstruct the data. The result shows small differences are in low latitude, which increase with latitude in the middle stratosphere and upper mesosphere.

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