1. Pavel TOROPOV, Vladimir MIKHALENKO, Stanislav KUTUZOV
Physical mechanisms of the intensive melting of glaciers of the North Caucasus in the last 20 years
Pavel TOROPOV, Vladimir MIKHALENKO, Stanislav KUTUZOV
Fac. of Geography
Institute of Geography

2. How the climate changed in the mountains last 20 years?
Tibetan plateau
&
Himalayas:
ΔT = 0.2 – 0.3 C
Andes:
ΔT = 0.3 – 0.4 C
Alps:
Pepin N., Bradley R. S., Diaz H. F., et al.
Elevation-dependent warming in mountain regions of the world. //
Nature Climate Change. Vol. 5. May pp

3. As a result of warming in the mountains rapid
melting of glaciers across the world

4. Degradation of the glaciers of the Central Caucasus:
Djankuat glacier (results from V. Popovnin)
Garabashi glacier
Cumulative mean
annual mass balance
Cumulative mean
annual mass balance
accumulation
accumulation
Ablation

5. How to estimate the climate change in the Caucasus? Using:
WMO’s meteorological station
Measurements of scientific expeditions
can not be used because:
a very small number of mountains stations
statistically heterogeneous series of observations
can not be used because:
a very short time-serials of measurements

6. The only way - is to use the reanalysis’s data…For example, NCEP/NCAR
Global model
of atmospheric
circulation
Global observation
data
We used NCEP/NCAR reanalysis’s data for
summer season since 1948 to 2011 years.
Spatial resolution of data: 2 x 2 degrees
Temporary resolution – 1 day
Using data: air temperature, wind and humidity on the geopotential surfaces 500, 700, 850 hPa (in free atmosphere)
reanalysis data were compared with the results of meteorological observations in the Elbrus expedition
Gridded meteo-data

7. Example of radiation budjets’s data, they were received in the Elbrus expedition 2013 (подписи осей, и т.д.)

8. How to estimate the reanalysis ‘ s data?
Western plateau, 5100 m
Eastern top, 5635 m
m.Elbrus
Terskol, 2200 m
Garabashi, 3850 m

9. Surface temperature according to our observations (red line) and reanalysis’s data (blue line)
01.VII VII 20.VII 30.VII 10.VIII 20.VIII
01.VII VII VII VII VIII VIII
01.VII VII VII VII 10.VIII 20.VIII
01.VII VII 20.VII 30.VII 10.VIII 20.VIII
T, °C
Eastern top, 5635 m
CORREL = 0.86
Garabashi, 3850 m
CORREL=0.81
Terskol, 2250 m
CORREL = 0.79
Western plateau, 5100 m
CORREL = 0.84

10. Wind speed according to our observations (green line) and reanalysis’s data (black line) on station Garabashi
Garabashi, 3850 m
CORREL=0.71

11. Temperature anomaly, renalisys data Wind speed anomaly, renalisys data
The air temperature and wind speed (Garabashi) during the season of ablation for the period , reconstructed according to the reanalysis NCEP/NCAR.
Temperature anomaly, renalisys data
Gaussian distribution
Temperature, °C
ΔV, м/с
Wind speed anomaly, renalisys data
Weibull distribution
Speed of wind, m/s
Скорость ветра, м/с

12. Frequency of wind direction according to the reanalysis data
Western plateau (5150 m)
Garabashi (3850 m)

13. The summer temperature changed not fast…But why Caucasian’s glaciers melts so fast?

14. The structure of the heat balance of the «warm» glacierВ
Pliq H LE
the contribution of the radiation budget in the melting: 85-90%

15. Comparison of the components of the heat balance of glaciers Dzhankuat (left) and Tyndall (right)

16. Components of the radiation budget of the Central Caucasus from reanalysis data
MJ/m2
Short-wave budget
Long-wave budget
Total radiation budget
Cumulative mean
annual mass balance

17. Spatial distribution of linear trends of temperature 1984 - 2015
WINTER, C/10yr
SPRING, C/10yr
SUMMER, C/10yr
AUTUMN, C/10yr

18. Spatial distribution of summer linear trends for 1984 - 2015
CAPE, Dj/kg
MOISTURE IN THE COLUMN, kg/m2
TREND OF CAPE, Dj/kg/10yr
TREND OF MOISTURE, kg/m2/10yr

19. Last 35 years in the summer is dominated by anticyclonic circulation
LINEAR TREND OF DIVERGENCE
LINEAR TREND OF VERTICAL SPEAD
MERIDIONAL SECTION OF TREND OF VERTICAL SPEAD

20. Conclusions
Increasing summer temperatures in the Central Caucasus in the last 20 years is statistically insignificant.
Intensive ablation in the last years, with an increase of radiation associated budget of 3-5% over the period
Similar results were obtained in the Alps, in particular in [Philipona, 2012]. In these studies analyzed the observational data - is very important.
The reason for the increase in the radiation budget of the Central Caucasus - the growth of total radiation budget – firstly, long-wawe component. It may be associated with an increase atmospheric humidity, and increase in the frequency of anticyclones