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Climate Change Tendencies in Georgia under Global Warming Conditions. Mariam Elizbarashvili 1 Marika Tatishvili 2 Ramaz Meskhia 2 Nato Kutaladze 3 1. Ivane Javakhishvili Tbilisi State University, 2. Georgian Technical University, Institute of Hydrometeorology.
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Climate Change Tendencies in Georgia under Global Warming Conditions Mariam Elizbarashvili1 Marika Tatishvili2 Ramaz Meskhia2 Nato Kutaladze3 1. IvaneJavakhishvili Tbilisi State University, 2. Georgian Technical University, Institute of Hydrometeorology 3. The National Environmental Agency, Georgia
Mountains cover a significant part of the territory: 54% of it is located at an altitude of 1,000 m above sea level. Mountains cover a significant part of the territory: 54% of it is located at an altitude of 1,000 m above sea level. Almost every climatic zone is represented in Georgia except for savannas and tropical forests. area - 67,900 km2 The Black Sea coastal zone has a humid subtropical climate. The average annual temperature there is 14-15OC, with extremes ranging from +45OC to -15OC, and annual amounts of precipitation vary between 1,500 mm and 2,500 mm. The Black Sea influences the climate of West Georgia, resulting in mild winters, hot summers and abundant precipitation. Here in the mountainous and high mountainous areas, the annual air temperature ranges from 6-10OC to 2-4OC with an absolute minimum between -30OC and -35OC, and annual amounts of precipitation range between 1,200-1,600 mm and 2,000 mm.
The climate in the plains of East Georgia is dry: in the lowlands, it is a dry subtropical climate, and in mountainous areas it is alpine. The average annual temperature is 11-13OC in the plains, and 2-7OC in the mountains. The absolute minima are -25OC and -36OC respectively. The absolute maximum reaches +42OC, and the absolute minimum falls to -42OC in the high mountains (the slopes of Mount Kazbegi). The annual amounts of precipitation vary in the range of 400-600 mm in the plains, and 800-1,200 mm in the mountains. Change in air temperature and precipitation between climate norms until 1960 and average values of the 1957-2006 period
Dynamics of Changes of Hydrometeorological Observation Network Points Meteorological posts Meteorological stations Hydrological posts Source: National Environmental Agency
BLACK SEA Temperature stations precipitation stations • Data sources: • The National Environmental Agency, Georgia
To restore data errors (missed data) following linear climatologic methods have been used: METHODS • 1. Method of corresponding differences • 2. Method of corresponding divisions.
Figure shows an example of comparison of actual and estimated average monthly temperatures in January at the Kazbegi alpine station over the period between 1936 and 1990, when this station was operational. Dependence between actual (x) and estimated (y) average January temperature at the Kazbegi alpine station over the period between 1936 and 1990, R2 determination coefficient
Multiyear flow of average annual air temperature and corresponding equation of regression: 1 - Tbilisi; 2 - Poti; 3 - Kazbegi alpine Multiyear flow of annual sum of atmospheric precipitations and corresponding equation of regression: 1 - Tbilisi; 2 - Poti
Precipitation distribution in 1936, January Temperature distribution for 1936 February.
The whole territory of Georgia was divided by 25 km. grid so that the territory have to be covered as many points as possible. So the 112 pointed 25 km. grid was created. Grid points with elevation
a) For air temperature • • Strong cooling (less than -0.10 ՕС during 10 years); • • Moderate cooling (-0.06- -0.10 ՕС during 10 years); • • Weak cooling (-0.02 - -0.06 ՕС during 10 years); • • Unchanged (-0.02- 0.02 ՕС during 10 years); • • Slight warming (0.02-0.06 ՕС during 10 years); • • Moderate warming (0.06-0.10 ՕС during 10 years); • • Strong warming (over 0.10 ՕС during 10 years). • b) For atmospheric precipitations • • Significant decrease (less than -5% during 10 years); • • Moderate decrease (-3.1- -5.0% during 10 years); • • Insignificant decrease (-1.1- -3.0 % during 10 years); • • Unchanged (-1- 1% during 10 years); • • Insignificant increase (1.1- 3.0% during 10 years); • • Moderate increase (3.1- 5.0% during 10 years); • • Significant increase (over 5% during 10 years). Depending on the intensity of warming (cooling), the following gradations of rate of changes were nominally determined:
Development and validation of 1936-2011 year high resolution monthly gridded temperature and precipitation data set for use in global climate change assessment for Georgia. Velocity of annual mean air temperature change oC in decade Velocity of January mean air temperature change oC in decade Precipitation annual sum variation velocity % in decade Velocity of July mean air temperature change oC in decade
Climate extreme indices (CEIs) used in this study are approved as core indices by the CCl/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI) • Climate extreme indices have been assessed using R and the RClimDex1.0 software. • Homogeneity and quality of the time-series were tested by the software package RHTestsV3 • GIS METHODS
(a) (b) Geoinformational maps of classification of maximum air temperature (a) Tmax and number of hot days (b) SU30 during a year within the period of 1961-1990.
The average value of some climate indices in different physical and geographical conditions over the basic WMO period (1961-1990).
Average value of the temperature indices for the different periods of averaging
The presented maps show that changes in temperature and precipitations in the territory of Georgia under global warming conditions are not of uniform nature due to complicated physical and geographic, and basically, orographic and landscape-climate conditions. Largest spots and territories of strong warming, when an average annual temperature increased by more than 0.1ՕС during 10 years, are observed in eastern Georgia. Spots of weak and moderate warming with the temperature increasing at the rate of 0.02-0.1ՕС during 10 years, are observed in western Georgia. • Over an insignificant part of Georgia, temperature remained almost unchanged or changed insignificantly. Decrease in temperature is observed mainly in western Georgia. Strong cooling occurs in a significant part of Adjara and northern part of Black Sea coast where an average annual air temperature decreased at the rate of over 0.1ՕС in 10 years. • Over a significant territory of East Georgia, annual sums of precipitation decreased at the rate of 1-3% during 10 years. The highest rate of decrease in precipitation is observed in Kvemo Kartli (south of Tbilisi), comprising more than 5% in 10 years. Increase in annual sums of precipitation is observed in several districts of West Georgia as well as in the central part of Iori Plateu in East Georgia where the annual sum of precipitation increased at the rate of 1-3% during 10 years. In mountainous Adjara and some other districts of Black Sea coast, the rate of increase in precipitations reached 5%. • For the period of 1991-2011, compared to the years of 1936-1960, the number of hot days has increased to 20. And the number of tropical nights-to 15. Compared to the basic WMO periods (1961-1990) – these changes made up 18 and 11 days respectively. The number of tropical nights in Tbilisi has increased to 6 days compared to the period until 1960. In Pasanauri, on the south slope of the Greater Caucasus, for the last period compared with the period of averaging, recommended by WMO (1960-1990) the number of hot days has increased to 17. CONCLUSIONS