seasonal fluctuations
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MAUSAM ◽  
2021 ◽  
Vol 43 (3) ◽  
pp. 321-324
Author(s):  
Y.A. GOUTSIDOU ◽  
T.J. MAKROGIANNIS ◽  
A.A. FLOCAS ◽  
C.S. SAHSAMANOGLOU

The data. used for this study form the time series of the annual and seasonal fluctuations of bare soil temperature values In Thessaloniki-Greece. The mean arrival value IS 20°C with a standard deviation of 1 .3°C. The winter is the most variable season. The analysis of these time series has shown that there were notable spells of years with values above or below the normal one. Negative trends were observed for the annual and seasonal values with the exception of winters. The well known QBO was found in the annual and spring time series.  


MAUSAM ◽  
2021 ◽  
Vol 64 (4) ◽  
pp. 687-698
Author(s):  
DR SIKKA ◽  
CS TOMAR ◽  
SI LASKAR ◽  
SUMAN GOYAL ◽  
AJIT TYAGI

Hkkjr esa xzh"edkyhu ekulwu ds nkSjku flukWfIVd vkSj mi&ekSleh mrkj p<+koksa dks le>us ds fy, o"kZ 2011 esa egk}hih; m".kdfVca/kh; vfHklj.k {ks= ¼lh-Vh-lh-tsM-½ ds uke ls Hkkjrh; ok;qeaMyh;&leqnzh foKku leqnk; us ,d QhYM dk;Zdze vk;ksftr fd;kA bl dk;Zdze dk ,d mís'; ekulwu ds flukWfIVd vkSj varjk&ekSleh mrkj&p<+koksa ls lacaf/kr c`greku ifjlapj.k ds dzfed fodkl ds ckjs esa tkudkjh izkIr djuk Hkh jgk gSA bl 'kks/k i= esa ekulwu 2011 ds le; cM+s iSekus ij gq, mrkj&Pk<+koksa ds ckjs esa Hkh crk;k x;k gSA o"kZ 2011 esa ekuwlu esa ekSle dh yxHkx lkekU; o"kkZ gqbZ rFkkfi mi&ekSleh eku ij twu ekg esa vPNh o"kkZ gqbZ] rRi'pkr tqykbZ ekg esa de o"kkZ gqbZ vksj fQj vxLr ekg ds vkjaHk ls ysdj flracj ekg ds var rd fQj ls vPNh o"kkZ gqbZA ekSle ds iwokZ)Z esa djhc&djhc U;wVªy yk&fuuk fLFkfr;k¡ cuhA rFkkfi vxLr ekg ls ysdj flracj ekg ds var rd Hkwe/;js[kh; iwohZ iz'kkar egklkxj esa leqnz lrg rkieku ¼,l-,l-Vh-½ lkekU; ls de ¼yk&fuuk fLFkfr;k¡½ esa ifjofrZr gks x,A gkykafd xaxk ds eSnkuh Hkkxksa esa fuEu {kksHkeaMy ij leqnz dh rjQ ls vkus okyh ok;q dk izokg cuk] ij iwjh _rq esa ok;q foy; yksM lkekU; ls cgqr de cus jgsA bl 'kks/k i= esa flukWfIVd ds fofHkUu igyq] iz'kkar egklkxj esa ,l-,l-Vh ds lqnwj izHkko ls lacaf/kr ekulwu ds miekSleh mrkj&p<+koksa rFkk Hkkjrh; leqnzh f}/zkqo ¼vkbZ-vks-Mh-½ ds LFkkuh; izHkko ij fopkj&foe'kZ fd;k x;kA blds lkFk&lkFk izpkyukRed lkaf[;dh; ekSle izkxqfDr ¼,u-MCY;w-ih-½ fun'kksZa] ;wjksih; e/; vof/k ekSle iwokZuqeku dsUnz ¼bZ-lh-,e-MCY;w-,Q-½] HkweaMyh; iwokZuqeku iz.kkyh ¼th-,Q-,l-½ vkSj ekSle vuqla/kku vkSj iwokZuqeku ¼MCY;w-vkj-,Q-½ ds fu"iknu ij Hkh fopkj&foe'kZ fd;k x;kA lh-Vh-lh-tsM- vkadM+ksa dk mi;ksx djrs gq, ekulwu 2011 ds fu"iknu ds vk/kj ij vkxs fd, tkus okys vuqla/kku ds dbZ {ks=ksa ds fo"k; esa Hkh lq>ko j[ks x,A  Indian atmosphere-ocean science community organised a field programme known as Continental Tropical Convergence Zone (CTCZ) during 2011 to understand the synoptic and sub-seasonal fluctuations of summer monsoon over India. One of the objectives of the programme was to understand the evolution of the large scale circulation in relation to synoptic & intra-seasonal fluctuations of the monsoon. The paper addresses the large scale fluctuations of Monsoon-2011. The Monsoon-2011 performed very close to the normal rainfall of the season. However, on the sub-seasonal scale its performance was good during June, became deficient during July and it recovered from the beginning of August to the end of September. The early part of the season was accompanied by near neutral La-Nina conditions. However, sea surface temperatures (SSTs) in the Equatorial Eastern Pacific Ocean shifted to below normal (La-Nina conditions) from August to the end of September. As the Gangetic Plain was swept by marine origin air stream in the lower troposphere, the aerosol load remained much below the normal during the entire season. The paper discusses different aspect of synoptic, sub-seasonal fluctuations of monsoon in relation to remote forcing of the SSTs in the Pacific and the local forcing of the Indian Ocean Dipole (IOD). Also the performance of the operational numerical weather prediction (NWP) models:  European Centre for Medium-Range Weather Forecasts (ECMWF), Global Forecast System (GFS) and Weather Research and Forecasting (WRF) is discussed. Several areas of further research using CTCZ data are also suggested based on the performance of the Monsoon-2011.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3607
Author(s):  
Shutaro Shiraki ◽  
Aung Kyaw Thu ◽  
Yutaka Matsuno ◽  
Yoshiyuki Shinogi

The two-layer Shuttleworth–Wallace (SW) evapotranspiration (ET) model has been widely used for predicting ET with good results. Since the SW model has a large number of specific parameters, these parameters have been estimated using a simple non-hierarchical Bayesian (SB) approach. To further improve the performance of the SW model, we aimed to assess parameter estimation using a two-level hierarchical Bayesian (HB) approach that takes into account the variation in observed conditions through the comparison with a traditional one-layer Penman–Monteith (PM) model. The difference between the SB and HB approaches were evaluated using a field-based ET dataset collected from five agricultural fields over three seasons in Myanmar. For a calibration period with large variation in environmental factors, the models with parameters calibrated by the HB approach showed better fitting to observed ET than that with parameters estimated using the SB approach, indicating the potential importance of accounting for seasonal fluctuations and variation in crop growth stages. The validation of parameter estimation showed that the ET estimation of the SW model with calibrated parameters was superior to that of the PM model, and the SW model provided acceptable estimations of ET, with little difference between the SB and HB approaches.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1297
Author(s):  
Peng-Wu Yin ◽  
Xian-Guo Guo ◽  
Dao-Chao Jin ◽  
Wen-Yu Song ◽  
Lei Zhang ◽  
...  

A 12-month consecutive investigation was made at Jingha village in southern Yunnan of southwest China from April 2016 to March 2017. A total of 2053 Indochinese forest rats (Rattus andamanensis Blyth, 1860) were captured and examined, which account for 84.69% (2053/2424) of all the animal hosts (rodents and other small mammals) at the investigation site. And 39.82% (13,531/33,980) of gamasid mites were identified from the body surface of R. andamanensis and they belong to 41 species, 10 genera, 3 subfamilies and 2 families. Of the 41 species of gamasid mites identified from R. andamanensis, Laelaps nuttalli Hirst, 1915 and Laelaps echidninus Berlese, 1887 were the most dominant with 70.63% and 20.67% of constituent ratios respectively. In monthly fluctuations of all the gamasid mites on R. andamanensis, the constituent ratio (Cr) and overall infestation mean abundance (MA) of the mites in 12 months showed two obvious peaks in January (winter season) and June (summer season). However, the two dominant mite species, L. nuttalli and L. echidninus, showed different patterns of seasonal fluctuations. Laelaps nuttalli occurred throughout the year, and its Cr and MA showed two prominent peaks in winter season (December and January) and summer season (June), which belongs to the summer-winter type of seasonal fluctuation. Laelaps echidninus also occurred on R. andamanensis throughout the year, but its Cr and MA showed only one peak in winter season (December and January), which belongs to the winter type of seasonal fluctuation. A negative correlation existed between two climatic factors (temperature and rainfall) and the infestations (Cr, prevalence PM and MA) of two dominant mite species (L. nuttalli and L. echidninus) on R. andamanensis (p < 0.05). Temperature and rainfall are considered to be two key factors that influence the seasonal fluctuations of the mites on the studied rat species.


2021 ◽  
Author(s):  
Elliot Jagniecki ◽  
Andrew Rupke ◽  
Stefan Kirby ◽  
Paul I nkenbrandt

Following the construction of the railroad causeway in 1959, a perennial halite (NaCl) bottom crust has been known to exist in the north arm (Gunnison Bay) of Great Salt Lake, Utah, but the lake conditions controlling accumulation or dissolution of the crust are not well defined, including how depth-controlled chemodynamic and hydrodynamic factors influence the degree of the halite saturation. Immediately prior to the opening of a new bridge in the causeway in early December 2016 when north arm lake elevation was at a historical low (just above 4189 feet), the north arm lake brine was at halite saturation. After the opening, inflow of less saline south arm water mixed with north arm water, raised lake elevation, and diluted the north arm lake brine to undersaturation with respect to halite. The following five years have resulted in annual and seasonal fluctuations of halite saturation states. Beginning in mid-2019, the Utah Geological Survey began a study of the north arm to better understand and document the transitions of halite saturation state following the bridge opening using newly collected data as well as reviewing available past data.


2021 ◽  
Author(s):  
I.I. Kirbizhekova ◽  
T.N. Chimitdorzhiev ◽  
A.K. Baltukhaev ◽  
A.V. Dmitriev ◽  
P.N. Dagurov

The article presents the results of assessing the restoration of a pine forest on a test site in the vicinity of Ulan-Ude after the 2003 fire and reforestation work. The studies were carried out on the basis of the full polarimetric information of the L-band ALOS-2 PALSAR-2 from 2017–2019. and NDVI indices based on the optical range of Resurs-P and Landsat 1995–2021. The results of the polarimetric decomposition of the H-F-a-classification indicate significant differences between the test and reference forest areas. Studies of long-term seasonal fluctuations of the NDVI for the test site revealed differences in the rate of recovery of multi-seasonal tracks to the pre-fire level and the level of the reference forest areas.


2021 ◽  
Author(s):  
◽  
Robin Alexander Fordham

<p>An account is given of ecological studies on the Southern Black-backed Gull Larus dominicanus Licht in which attention is directed to the structure and balance of the Wellington population. This population is large; in the 1963-64 season more than 5,600 pairs were breeding in the study area, and the peak non-breeding season population in 1964 exceeded 12,000 birds. Its growth has been closely associated with the increase of the human population, and the present distribution and dispersal of gulls is strongly influenced by the distribution of " artificial" feeding sites such as refuse tips and meatworks. The population is composed of breeding colonies, night roosting flocks and daily communal flocks which are inter-related by the social activities and dispersal of the birds. Thus the population is more or less integrated, rather than simply comprising discrete geographic units. Seasonal fluctuations in size and age composition of communal flocks are discussed. Breeding success varies between colonies. It is affected by mammalian predation in some, and by drowning in others, while the largest colonies are comparatively safe for breeding birds. The rapid growth of the whole population in the last five to 10 years appears to have some influence on nesting density, clutch size, spread of laying and overall breeding success. In recent years production of young has been twice that required to maintain the population which has grown at the rate of not less than 7.2% annually. Mortality of banded gulls inside and outside the colony is described and the influence of several factors on chick mortality examined. The principal factor limiting the population appears to be the food supply in relation to the number of birds. When numbers increase and the food supply diminishes, major regulation of the population is apparently achieved in the colony by predation (but not cannibalism) of young by adults. Dispersal of banded gulls from the Wellington colonies is very restricted.</p>


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