14. starptautiskā konference 2012 - Latvijas Jūras akadēmija

Air temperature, deg CProceedings of 14th International conference „Maritime Transport and Infrastructure - 2012”987654y = 0.0031x + 0.214531780 1810 1840 1870 1900 1930 1960 1990 2020YearsFig. 2 Average air temperature changes in Riga at time period from 1795 to 2011Table 1The general tendency of air temperature changes in Riga, at value of o C/100 years for different periodsTime period years 1795-2011 1840-2011 1900-2011 1960-2011Tendency of airtemperature changes,C/100 years0.31 0.69 1.37 3.732. Levels of waterLevels of water are being influenced by astronomical conditions, fresh water balance, unevenatmospheric pressure, and wind /water density mutual rates. Water level changes in Baltic Sea arebeing under direct impact from endogenous fresh water flow fluctuations, changes of atmosphericpressure and winds; there are some direct relations of such changes with melting of ice cover andEarth crust’s vertical shifts. This title covers annual average changes of the levels of water in Ventspilsand Daugavgriva at time period from 1873 to 1968. Both locations are characterized by clear tendencyof water level growth – in the Daugavariver the level of water has grown by 20.5 cm per 100 years, inVentspils water level has grown by 4.4 cm/100 years (Fig. 5).The interest sparking finding is that the average speed (rate) of water level growth in bothlocations is quite different. This difference could be explained by Earth crust’s lithospheric verticalshifts in Baltic region. There are no significant vertical lithospheric shifts in Daugavgriva, but averagevertical lithospheric movement rate in Ventspils is about 0.6-1.0 mm/year, providing 6-10 cm/100years [7]. The assumption is that water level fluctuations in Daugavgriva are in direct relation with thetrends of Ocean water level, in turn, Ventspils indicators are under impact from Earth crust’slithospheric vertical shifts.124