AndreyAndrey G. G. KostianoyKostianoyP.P. P.P. ShirshovShirshov Institute of Institute of OceanologyOceanology, , Russian Academy of Sciences Russian Academy of Sciences

Sergey A. LebedevSergey A. LebedevGeophysical Center, Russian Academy of SciencesGeophysical Center, Russian Academy of SciencesState Oceanographic InstituteState Oceanographic Institute

JeanJean--FranFranççois Crois Créétaux & Stephane Calmanttaux & Stephane CalmantLegos, Toulouse, FranceLegos, Toulouse, France

Stephano VignudelliStephano VignudelliCNR, Pisa, ItalyCNR, Pisa, Italy

Estimating the Caspian Estimating the Caspian Sea level and Volga river Sea level and Volga river runoff from satellite runoff from satellite altimetryaltimetry

Second Space for Hydrology Workshop, Nov 12-14, 2007, Geneva

The Caspian Sea presents the world’s largest isolated water reservoir, with features including its size, depth, chemical properties, thermohaline structure and water circulation enable to classify it as a deep inland sea. Currently its level is at –27 meters, it occupies an area of 392000 km2, with maximum depth of 1025 m.The isolation of the Caspian Sea from the ocean and its inland position are responsible for a great importance of the outer thermohydrodynamic factors, in particular, the heat and water fluxes through the sea surface, and river runoff for the sea level variability, formation of its 3D thermohaline structure and water circulation.

The CaspianThe Caspian SeaSea

Caspian Sea level variationsand water balance from satellite altimetry

Seasonnal and interannuel dynamic topography of the Caspian Sea from altimetry

and hydrodynamical model

Caspian Sea data base and Cal/Val activities

Over the past half-century, there was a

regression of the Caspian Sea until 1977

when the sea level lowered to −29 m. This

drop is considered to be the deepest for the last 400 years. In 1978 the water level started to

rise rapidly, and now it has stabilized near

the −27 m level. 1840 1860 1880 1900 1920 1940 1960 1980 2000Time (year)

-29

-28

-27

-26

-25

Sea

Leve

l (m

)

The change in the tendancy of the mean sea level variations that occured In the mid 70s, followed by abrupt rise, represents an important indicator of

The changes in the natural regime of the Caspian Sea

The The CaspianCaspian SeaSea LevelLevel VariationVariation

1

2

3

4

56

7 8

209-092

133-092

133-244

057-092

209-016 031-092

031-016 107-092

47 ° 49 ° 51 ° 53 ° 55 °

47 ° 49 ° 51 ° 53 ° 55 °

36 °

38 °

40 °

42 °

44 °

46 °

36 °

38 °

40 °

42 °

44 °

46 °

244

235

209

194

168

133

107

092

066

057

031

016

Southern Part

Middle Part

Northern Part

Temporal Variability of Sea Surface andTemporal Variability of Sea Surface andVolga river water height, from satellite altimetry: Volga river water height, from satellite altimetry:

T/P, Jason, GFO, and T/P, Jason, GFO, and EnvisatEnvisat

235

168

057092

47 ° 49 °

47 ° 49 °

45 °

46 °

47 °

45 °

46 °

47 °

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004Time (year)

-30

-29

-28

-27

-26

Volg

a R

iver

wat

er h

eigh

t (m

)

010

2030

40M

ean

mon

thly

wat

er d

isch

arge

of

Volg

ogra

dska

ya h

ydro

-pow

er s

tatio

n (m

3 ·103 /s

)

123

-27

-26,8

-26,6

-26,4

-26,2

-26

-25,8

1992 1994 1996 1998 2000 2002 2004 2006 2008Date (yr)

Leve

l (m

)

-28-27,8-27,6-27,4-27,2

-27-26,8-26,6-26,4-26,2

-26

1992 1994 1996 1998 2000 2002 2004 2006

Date (yr)

Leve

l (m

)Caspian Sea level above Baltic Sea

Topex/Poseidon, Jason, GFO, Envisat

+ Hypsometry curve

Water Balance of Caspian SeaTotal Runoff river to Caspian Sea

150

200

250

300

350

400

450

1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

date (year)

Run

off (

km3 )

Runoff to Kara Bogaz Gol

0

10

20

30

40

50

60

1870 1890 1910 1930 1950 1970 1990 2010

Date (year)

Run

off (

km3 )

(E-P) deduced from altimetry and in situ data over Caspian Sea (positiv underground water of 4 km3

was taken)

300

400

500

600

700

800

900

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Date (year)

E-P

(mm

)

Variation of volume of Caspian Sea

73950

74000

74050

74100

74150

74200

74250

74300

74350

74400

74450

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Date (year)

Volu

me

(km

3 )

The Caspian Sea The Caspian Sea Level Rate Level Rate

Mean SSH difference between: 1995 and 1993; 1997 and 1995, revealed from the GCRAS05 MSS Model

The rate of the Caspian Sea SSH change revealed from the T/P and J1 satellite altimetry data

(October 1992 - December 2005

1993 –1995 18.2 ± 3.8 22.8 ± 2.5 20.9 ± 4.9 21.1 ± 4.11995 –1997 -18 ± 1.4 -13.9 ± 1.8 -18 ± 5.6 -24 ± 5.01997 –1999 -3.6 ± 1.5 -6.2 ± 1.7 -5.4 ± 4.3 -5.3 ± 3.21999 –2001 -8.7 ± 2.7 -8.4 ± 1.7 -12 ± 2.4 -9.3 ± 2.92001 –2003 8.9 ± 4.6 7.0 ± 5.3 10.6 ± 6.3 9.1 ± 4.4

Time periodRate of Change, (cm/yr)

Whole Sea

Northern Part

Middle Part

Southern Part

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

в.д.с.ш. 47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

в.д.с.ш.

1995–19971993–1995

Analysis of Spatial and Temporal Variability Analysis of Spatial and Temporal Variability of Dynamic Topographyof Dynamic Topography

Dynamic topography maps were used to analyze the spatial and temporal variability of the general dynamics in the Caspian Sea. They were constructed on the basis of the superposition of the sea level anomalies distribution over the climatic dynamic topography.The sea level anomalies were calculated from altimetry data.The climatic dynamic topography (or hydrodynamic level) was calculated from three dimensional baroclinic model with free surface. Average monthly fields of temperature and salinity, climatic Volga River run-off and irregular evaporation from sea surface were taken in consideration. Also atmospheric pressure and wind fields from the regional model over the period from 1948 to 2005 were used. This model was developed in Laboratory of Sea Applied Research of Hydrometeorological Research Center of Russian Federation.

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

Averaged dynamic topography (cm) from numerical

hydrodynamic model (Popov, 2004)

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

October

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

July

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

April

47° 49° 51° 53° 55°

47° 49° 51° 53° 55°

36°

38°

40°

42°

44°

46°

36°

38°

40°

42°

44°

46°

January

DynamicDynamic TopographyTopography SeasonalSeasonal VariabilityVariability

Average annual variation of CSL

-0.25

-0.15

-0.05

0.05

0.15

0.25

0 2 4 6 8 10 12 14

Date (month)

rela

tive

CSL

/ann

ual

aver

age

(m)

Geographycal distribution of annualCSL variation deduced from 10 years(1993-2002) Of Topex / Poseidon dataand average seasonal variations

Annual Amplitude (m)

Monthly CS volume / annual average (Red) and monthly average Volga river Discharge (Black)

-80

-60

-40

-20

0

20

40

60

80

0 1 2 3 4 5 6 7 8 9 10 11 12 13Date (month)

Volu

me

(km3 )

CASPIAN SEA DATA BASE

Comparison of Satellite Data Comparison of Satellite Data and Level Gauges Dataand Level Gauges Data

Correlation coefficients and RMS between average monthly data of sea level gauge measurements and SSH derived from satellite altimetry data. Red markers show correlation between data in the Middle Caspian Sea and blue markers – in the Southern Caspian Sea

Correlation coefficients between average monthly data of sea

level gauge measurements and sea level derived from satellite

altimetry data since October 1992 till December 2005

0.18

0.17

0.16

0.15

0.14

RMS (m)

0.8 0.85 0.9 0.95 1Coefficient of Correlation

057-092 133-244 133-092 209-092 209-016 031-092 031-016

(1) Makhachkala 0,876 0,859 0,923 0,931 0,918 0,931 0,892 0,938(2) Fort Shevchenko 0,899 0,739 0,862 0,853 0,901 0,883 0,874 0,906(3) Zhiloy Island 0,876 0,863 0,948 0,942 0,932 0,931 0,901 0,950(4) Kara-Bogaz-Gol 0,876 0,876 0,943 0,942 0,941 0,948 0,901 0,953(5) Turkmenbashi 0,841 0,889 0,951 0,960 0,913 0,919 0,892 0,941(6) Baku 0,859 0,874 0,952 0,953 0,925 0,954 0,937 0,958(7) Neftyanyye Kamni 0,861 0,850 0,918 0,933 0,914 0,948 0,908 0,940(8) Kuuli Mayak 0,880 0,831 0,925 0,932 0,922 0,942 0,912 0,946

0,909 0,876 0,963 0,964 0,956 0,966 0,936 0,978

Mid

dle

Part

Sout

hern

Pa

rt

Whole Sea (level gauges)

Crossover Points

Level gaugesWhole

Sea(altimetry)

Northern Part Middle Part Southern Part

Makhashkala - Krasnovodsk

-0,1

0

0,1

0,2

0,3

0,4

0,5

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994

Date (year)

diffe

renc

e (m

)

Makhashkala - Ogurshink

-0,2

-0,1

0

0,1

0,2

0,3

0,4

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994

date (year)

Diff

eren

ce (m

)

Makhashkala-Kulaly

-0,2-0,1

00,10,20,30,40,50,60,7

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994

Date (year)

diffe

renc

e (m

)

Jilov - Baku

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0

0,1

0,2

0,3

0,4

0,5

0,6

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

Day / January 1, 1999

Sea

leve

l diff

eren

ce (m

)

Average: 13 cm

CASPIALT & ALTICORE Project

Installation of few new gauges along the Caspian Sea shorelines

Temporal and permanent GPS levelling

Mean altimetry profile calibratedby GPS campaign

Integrated Caspian Sea database

Sponsored by INTAS, UNESCO, GLOSS,Azerbaidjan and russian Academy of Sciences

Visit of a potential new Bottom Pressure Tide Gauge site

First results of Caspian Sea 2005 GPS Campaign

PerspectivesImprovement and interpretation

of CS water balance

Study impact of:changes in river runoff

global warming Irrigation in the Volga basin

Assimilation of altimetryIn models for study of Dynamic topography of the CS

Geographycall changes in temperature, precipitations and levelIncreasing the spatial distribution (Envisat, Altika)

Creation and maintaince of in situ and remote sensingData base

Caspialt projectCal/val of current and future altimetry

Enhance the international cooperation in the area of CS