Degree of connectivity in reconstructed precipitation dynamics and extremes for semiarid regions across South Siberia

2021 ◽  
pp. 125903
Author(s):  
Anastasiya V. Demina ◽  
Liliana V. Belokopytova ◽  
Dina F. Zhirnova ◽  
Nivedita Mehrotra ◽  
Santosh K. Shah ◽  
...  
Author(s):  
Vladimir Ponomarev ◽  
Vladimir Ponomarev ◽  
Elena Dmitrieva ◽  
Elena Dmitrieva ◽  
Svetlana Shkorba ◽  
...  

Multiple scale climate variability in Asia of temperate and high latitudes, Pacific, Indian and South Oceans, their features and linkages are studied by using statistical analyses of monthly mean time series of Hadley, Reynolds SST, surface net heat flux (Q), atmospheric pressure (SLP), air temperature (SAT) from NCEP NCAR reanalyses (1948-2015). Three multidecadal climatic regimes were revealed for the whole area studied by using cluster analyses via Principal Components of differences between values of Q, SLP, SAT in tropical and extratropical regions of the Asian Pacific, Indian and Southern Oceans. The climate regime change in 70s of the 20th century in this area is confirmed by this method. It is also found that the climate regime is significantly changed at the end of the 20th century in both same area and World Ocean. The characteristic features of recent climate regime after 1996-1998 are SLP increase in the central extratropic area of Indian Ocean, North and South Pacific being prevailing in boreal winter. It is accompanying SLP increase and precipitation decrease in South Siberia and Mongolia prevailing in boreal summer. Inversed SLP and precipitation anomaly associated with increase of cyclone activity and extreme events in the land-ocean marginal zones including Southern Ocean, eastern Arctic, eastern Indian, western and eastern Pacific margins. It is known that low frequency PDO phase is also changed at the same time.


Author(s):  
Vladimir Ponomarev ◽  
Vladimir Ponomarev ◽  
Elena Dmitrieva ◽  
Elena Dmitrieva ◽  
Svetlana Shkorba ◽  
...  

Multiple scale climate variability in Asia of temperate and high latitudes, Pacific, Indian and South Oceans, their features and linkages are studied by using statistical analyses of monthly mean time series of Hadley, Reynolds SST, surface net heat flux (Q), atmospheric pressure (SLP), air temperature (SAT) from NCEP NCAR reanalyses (1948-2015). Three multidecadal climatic regimes were revealed for the whole area studied by using cluster analyses via Principal Components of differences between values of Q, SLP, SAT in tropical and extratropical regions of the Asian Pacific, Indian and Southern Oceans. The climate regime change in 70s of the 20th century in this area is confirmed by this method. It is also found that the climate regime is significantly changed at the end of the 20th century in both same area and World Ocean. The characteristic features of recent climate regime after 1996-1998 are SLP increase in the central extratropic area of Indian Ocean, North and South Pacific being prevailing in boreal winter. It is accompanying SLP increase and precipitation decrease in South Siberia and Mongolia prevailing in boreal summer. Inversed SLP and precipitation anomaly associated with increase of cyclone activity and extreme events in the land-ocean marginal zones including Southern Ocean, eastern Arctic, eastern Indian, western and eastern Pacific margins. It is known that low frequency PDO phase is also changed at the same time.


2018 ◽  
Vol 932 (2) ◽  
pp. 22-35
Author(s):  
S.B. Kuzmin ◽  
D.A. Lopatkin

Mapping of hazardous geomorphological processes in the Baikal Region and its ecological and geomorphological zoning was carried out on the basis of the improved method, developed earlier by the authors. Baikal Region includes the subjects of the Russian Federation in the South Siberia and Republic of Mongolia within the boundaries of the Lake Baikal Basin. The basis of zoning are


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 174
Author(s):  
Elena A. Babushkina ◽  
Dina F. Zhirnova ◽  
Liliana V. Belokopytova ◽  
Nivedita Mehrotra ◽  
Santosh K. Shah ◽  
...  

Improvement of dendrochronological crops yield reconstruction by separate application of earlywood and latewood width chronologies succeeded in rain-fed semiarid region. (1) Background: Tree-ring width chronologies have been successfully applied for crops yield reconstruction models. We propose application of separated earlywood and latewood width chronologies as possible predictors improving the fitness of reconstruction models. (2) Methods: The generalized yield series of main crops (spring wheat, spring barley, oats) were investigated in rain-fed and irrigated areas in semiarid steppes of South Siberia. Chronologies of earlywood, latewood, and total ring width of Siberian larch (Larix sibirica Ledeb.) growing in forest-steppe in the middle of the study area were tested as predictors of yield reconstruction models. (3) Results: In the rain-fed territory, separation of earlywood and latewood allowed increasing variation of yield explained by reconstruction model from 17.4 to 20.5%, whereas total climatic-driven component of variation was 41.5%. However, both tree-ring based models explained only 7.7% of yield variation in the irrigated territory (climate inclusion increased it to 34.8%). Low temperature sensitivity of larch growth was the main limitation of the model. A 240-year (1780–2019) history of crop failures and yield variation dynamics were estimated from the actual data and the best reconstruction model. (4) Conclusions: Presently in the study region, breeding of the environment-resistant crops varieties compensates the increase of temperature in the yield dynamics, preventing severe harvest losses. Tree-ring based reconstructions may help to understand and forecast response of the crops to the climatic variability, and also the probability of crop failures, particularly in the rain-fed territories.


Author(s):  
T. V. Prabhakar ◽  
H. S. Jamadagni ◽  
Hendrik Knoche ◽  
P. R. Sheshagiri Rao

2002 ◽  
Vol 82 (4) ◽  
pp. 489-498 ◽  
Author(s):  
B G McConkey ◽  
D. Curtin ◽  
C A Campbell ◽  
S A Brandt ◽  
F. Selles

We examined 1990-1996 crop and soil N data for no-tillage (NT), minimum tillage (MT) and conventional tillage (CT) systems from four long-term tillage studies in semiarid regions of Saskatchewan for evidence that the N status was affected by tillage system. On a silt loam and clay soil in the Brown soil zone, spring what (Triticum aestivum L.) grain yield and protein concentration were lower for NT compared with tilled (CT or MT) systems for a fallow-wheat (F-WM) rotation. Grain protein concentration for continuous wheat (Cont W) was also lower for NT than for MT. For a sandy loam soil in the Brown soil zone, durum (Triticum durum L.) grain protein concentration was similar for MT and NT for both Cont W and F-W, but NT had higher grain yield than MT (P < 0.05 for F-W only). For a loam soil in the Dark Brown soil zone, wheat grain yield for NT was increased by about 7% for fallow-oilseed-wheat (F-O-W) and wheat-oilseed-wheat (W-O-W) rotations. The higher grain yields for NT reduced grain protein concentration by dilution effect as indicated by similar grain N yield. However, at this site, about 23 kg ha-1 more fertilizer N was required for NT than for CT. Elimination of tillage increased total organic N in the upper 7.5 cm of soil and N in surface residues. Our results suggest that a contributing factor to decreased availability of soil N in medium- and fine-textured soils under NT was a slower rate of net N mineralization from organic matter. Soil nitrates to 2.4 m depth did not indicate that nitrate leaching was affected by tillage system. Current fertilizer N recommendations developed for tilled systems may be inadequate for optimum production of wheat with acceptable grain protein under NT is semiarid regions of Saskatchewan. Key words: Tillage intensity, N availability, soil N fractions, N mineralization, crop residue decomposition, grain protein


2003 ◽  
Vol 23 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Marek Koutny ◽  
Jan Ruzicka ◽  
Jiri Chlachula

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