Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma Global Warmg ad Caspa Sea Level Fluctuatos Reza Ardakaa, Seyed Hamed Alemohammad Asssstat Professor, Departmet of Cvl Egeerg, Sharf Uversty of Techology, P.O. Box: 55-933, Tehra, Ira, Emal: ardakaa@cvl.sharf.edu Graduate Studet, Departmet of Cvl Egeerg, Sharf Uversty of Techology, P.O. Box: 55-933, Tehra, Ira, Emal: alemohammad@cvl.sharf.edu Abstract Coastal regos have a hgh socal, ecoomcal ad evrometal mportace. Due to ths mportace the sea level fluctuatos ca have may bad cosequeces. I ths research the correlato betwee the creasg tred of temperature coastal statos due to Global Warmg ad the Caspa Sea level has bee establshed. The Caspa Sea level data has bee receved from the Jaso- satellte. It was resulted that the mothly correlato betwee the temperature ad sea level s hgh ad also postve ad almost the same for all the statos. But the yearly correlato was egatve. It meas that the sea level has decreased by the crease temperature. - Itroducto After the Idustral Revoluto the emsso of gree house gases to the atmosphere has creased by a sgfcat rate. Accordg to the statstcs, the amout of Carbo Doxde, as oe of the most mportat gree house gases, has creased from 80 ppm 750 to 379 ppm 005 []. Of course ths crease has had a bgger rate the latest decades. Due to ths crease the global temperature has bee rse whch results chagg the statoary tred of the clmate varables of the earth. Ths pheomea has bee ettled Clmate Chage. I recet years may researches has bee doe to determe the effects of Clmate Chage o water cycle ad t s compoets lke precptato, sow ad etc. Oe of the most mportat effects of clmate chage that has bee dscovered s the chages that result sea level. Page
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma The IPCC 4th Assessmet Report states that Preset-day sea level chage s of cosderable terest because of ts potetal mpact o huma populatos lvg coastal regos ad o slads. The curret rate of sea level rse has bee reported to be -.5 mm/yr the 0th cetury []. Moder satellte measuremets reveal that sce 993, sea-level has bee rsg at a average rate of about 3 mm/yr, substatally faster tha the average for the 0th cetury of about.7 mm/yr, estmated from coastal sea-level measuremets. The ma cotrbutos to the 0th ad st cetury sea-level chage are: Thermal expaso of the oceas (water expads as t warms), The addto of mass to the oceas from the meltg of glacers ad ce caps regos lke Hmalayas, Alaska, Patagoa, etc., The exchage of mass wth the ce sheets of Atarctca ad Greelad, The exchage of mass wth terrestral water storages (groudwater, aqufers, dams, lakes) Caspa Sea s the bggest lake the world. It s located betwee the Europe ad South West of Asa. Ira, Azerbaja, Kazakhsta, Russa ad Turkmesta are the eghbors of the sea. As Caspa Sea has may sources of Ol ad Gas t has a very ecoomcal ad evrometal mportace. Due to the mportace of the sea ts fluctuatos wll be cosderable. M.R. Meshka ad A. Meshka (999) modeled the Caspa Sea Level Fluctuatos usg a stochastc modelg. I ther research a dyamc correlato has bee establshed betwee the precptato ad temperature Badar-e-Azal stato ad the Sea Level. But o cosderato has bee made to the treds of he temperature due to global warmg. [3] Nadeov (00) has used a olear model to predct the varatos of the Caspa Sea level chage. The seawater budget has bee descrbed by a system of olear stochastc dfferetal equatos [4]. Loehle (004) has aalyzed two 300-year temperature seres to detect the chage temperature. Seve models have bee ftted to the seres whch had t cotaed the 0th cetury data. The projectos of the sx of the models have show a warmg tred over the 0th cetury smlar tmg ad magtude to the Norther Hemsphere strumetal seres [5]. Elgud ad Gorg (007) has smulated the Caspa Sea Level Fluctuatos usg the results of the outputs of the Regoal Clmate Model. They have cosdered the A scearo as the stuato 07 00 ad the sea level has bee predcted usg the Regoal Clmate Model resulted form the Global Clmate Model. They Iteratoal Pael of Clmate Chage (IPCC) Page
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma have cocluded that the sea level wll decrease much more tha that of the 0 th Cetury. [6] I ths research we are gog to search o a correlato betwee the sea level data ad the temperature data at coastal gauges. The ecessary sea level data has bee accessed through the Jaso-sattelte. The temperature data at 7 coastal statos has bee receved from the Natoal Meteorologcal Orgazato of Ira. As the satellte data are avalable from September 99 ad the temperature data are avalable up to 005, the perod of September 99 to December 005 has bee selected for the aalyss perod. I the followg a short descrpto of the Jaso- satellte ad also the workg procedure addto to the cocluso wll be preseted. - Data Descrpto Use of satelltes to measure the sea levels has more ad more creased recet decades. The U.S. Departmet of Agrculture's Foreg Agrcultural Servce, cooperato wth the Natoal Aeroautcs ad Space Admstrato 3, ad the Uversty of Marylad, are routely motorg lake ad reservor heght varatos for approxmately 00 lakes located aroud the world. Ths project s uque, beg the frst of ts kd to utlze ear-real tme radar altmeter data over lad water bodes a operatoal maer. Surface elevato products are produced va a semautomated process. The project utlzes ear-real tme radar altmeter data from the Posedo- strumet o-board the Jaso- satellte whch was lauched December, 00. I addto, hstorcal archve data s used from the TOPEX/POSEIDON msso (99-00). The data avalable ths project are relatve lake heght varatos computed from TOPEX/POSEIDON (T/P) ad Jaso- altmetry wth respect to a 0 year mea level derved from T/P altmeter observatos. I ths research the Caspa Sea level data has bee used from ths project to decrease the possble errors the tde gauge measuremets. Fgure shows the mothly Caspa Sea level fluctuatos from September 99 to December 005 drve from 0-day Jaso- data. I the perod of 99-005 there were 8 moths that have two seres of data: oe from the TOPEX/POSEIDON ad the other form the Jaso-. Data used for these moths, whch cota Jauary 00 to August 00, are the averages from both satelltes. USDA-FAS 3 NASA Page 3
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma Fg Mothly Caspa Sea level fluctuatos wth respect to the 0 year mea The temperature data has bee used seve statos amely: Astara, Badar-e- Azal, Rasht, Ramsar, Noushahr, Babolsar ad Gorga. The data has bee derved form the yearly reports of the Natoal Meteorologcal Orgazato of Ira. As a example the yearly seres of temperature at Astara stato from 986 to 005 has bee show fgure. Fg Yealry temperature at Astara stato Page 4
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma 3- Data Aalyss Two ma steps are preseted here: Frst, detectg the tred temperature tme seres of the statos, secod, detectg the correlato betwee the temperature ad sea level. 3-- Tred Detecto To detect the tred a tme-seres we wll use two methods: - Cumulatve Devato Test - Regresso Aalyss Each of these methods wll be descrbed the followg: - Cumulatve Devato Test Ths test s defed o the bass of the cumulatve devatos from the mea, as t follows: k ( Y Y ), k = Sk =,..., () whch: Y : are the tme-seres data Y : s the mea of Y : s the umber of data the the S * k wll be defed such as: S * k D Y S = = k ( Y Y ) D Y () (3) Accordg to the value of S * k the Q parameter whch s the sestvty to the devato from the mea s defed as: Q = max S 0 k * k (4) Page 5
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma For 95% cofdece terval the Q parameter should be less tha.7 so that we ca say there s o tred. - Regresso Aalyss I ths test a smple regresso equato wll be calculated for the seres the form: Y = a + bx (5) I whch: Y s the depedet varable (ex. sea level) ad X s the depedet varable (ex. temperature) a ad b are the coeffcets of the regresso whch wll be calculated usg the least square method. To test the sgfcace of the b (slope of the tred) the T parameter should be calculated as below: b T = MSE S xx = ( X X ) S xx (6) (7) whch MSE s the Mea Square of the Errors. The absolute value of the calculated value of the T should be compared to T < tα the the slope s sgfcat., t α,, f 3-- Correlato Detecto The secod aalyss has bee made to detect the correlato betwee the temperature ad sea level. I ths regard the correlato coeffcet has bee calculated usg (8). r zy = z z y z z y y y (8) I whch z ad y are two tme seres (ex. temperature ad sea level). Page 6
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma The correlato has bee calculated for mothly, seasoal ad yearly data. It meas three dfferet correlato coeffcets has bee calculated for each stato, oe for the mothly temperature data ad mothly sea level, the other for the seasoal temperature data ad seasoal sea level ad the last oe for the yearly temperature data ad yearly sea level. For the seasoal data the ormal seasos of the year (Sprg, Summer, Autum ad Wter) has bee cosdered. 4- Results The results are dvded to two parts, frst the results of the tred tests ad secod the results of the correlato coeffcet. Table shows the results of the tred tests. I the Regresso Aalyss the cofdece terval to clculate t α has bee chose to be 95%. Also, Fgure 3, shows three sample statos data wth the tred le plotted o the mothly temperature data. Table - The results of the tred tests for the temperatuare Cumulatve Stato Devato Test Regresso Aalyss Q Tred b T t Tred Astara.7848 Yes 0.06 0.33408.009 Yes Babolsar.900 Yes 0.06 0.478.009 Yes Bada-e-Azal 4.378 Yes 0.0009 0.0064.009 Yes Gorga 8.3 Yes 0.00 0.0074.009 Yes Noushahr 6.008 Yes 0.03 0.8933.05 Yes Ramsar 8.7054 Yes 0.03 0.09604.009 Yes Rasht 4.665 Yes 0.07 0.0979.009 Yes Page 7
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma Rasht Stato Ramsar Stato Babolsar Stato Fg 3 Yearly tme seres of temperatuare wth ther tred le Page 8
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma The secod part of the results cota the correlato coeffcets betwee the sea level elevato ad the temperatuare at dfferet statos. As It was metoed before the correlatos coeffcet has bee caclculated for mothly, seasoal ad yearly seres for each stato. Table shows the results. Table The correlato coeffcets betwee the tempreatuare ad sea level Stato Mothly Correlato Coeffcets Seasoal Correlato Coeffcets Yearly Correlato Coeffcets Astara 0.5653966 0.544004-0.876049 Bada-e-Azal 0.55395 0.58567-0.335678 Rasht 0.5666350 0.3880966-0.8400 Ramsar 0.546543 0.335539-0.3404678 Noushahr 0.5577893 0.355480-0.349657 Babolsar 0.560099 0.5389376-0.379335 Gorga 0.5609775 0.3760694-0.4868 5- Cocluso As t was show the last secto all the statos have tred ther yearly temperature seres, accordg to the results of the both tests. Ths s a dcato of the Clmate Chage ad shows the eed for more assessmet ad research. The correlato coeffcet for the mothly seres all stato was postve, hgh ad almost the same amout. But, although the seasoal correlato was postve, t was t the same for all statos. The mportat thg s that the yearly correlato coeffcets were all egatve. Ths meas that although the yearly tred the temperature was postve (creasg) the yearly tred sea level s egatve (decreasg). Fally we ca say that a crease the yearly temperature results decrease of the sea level. Of course the decreasg tred ca be detected through the regresso aalyss the sea level data. The Caspa Sea Level Fluctuatos result from may parameters that temperature s oe of them ad a study of the correlato betwee the sea level ad temperature aloe ca t determe the tred sea level. It s worth metog that the mothly correlato coeffcets had a hgh postve value. It s suggested to cosder other Page 9
Iteratoal Coferece o Water Resources ad Clmate Chage the MENA Rego -4 November 008, Muscat, Oma parameters such as precptato, ar pressure, etc for modelg the tred sea level data. 6- Refereces [] IPCC (007). Clmate Chage 007: The Physcal Scece Bass. Cotrbuto of Workg Group I to the Fourth Assessmet Report of the Itergovermetal Pael o Clmate Chage [Solomo, S., D. Q, M. Mag, Z. Che, M. Marqus, K.B. Averyt, M. Tgor ad H.L. Mller (eds.)]. Cambrdge Uversty Press, Cambrdge, Uted Kgdom ad New York, NY, USA, 996 pp. [] Gortz, V. (000). Impoudmet, groudwater mg, ad other hydrologc trasformatos: Impacts o global sea level rse. Sea Level Rse: Hstory ad Cosequeces (B.C. Douglas, M.S. Kearey, ad S.P. Leatherma, Eds.), p. 97-9. [3] Meshka, M.R. ad Meshka, A., (997) Stochastc modelg of the Caspa sea level fluctuatos, Theoretcal ad Appled Clmatology, 58, pp. 89-95. [4] Nadeov, V.I. ad Shveka, V.I. (00). A Nolear Model of Level Varatos the Caspa Sea. J. of Water Resources, 9 (), p. 60-67. [5] Loehle, C. (004). Clmate chage: detecto ad attrbuto of treds from log-term geologc data. J. of Ecologcal Modellg, 7, p. 433-450. [6] Elgud, N. ad Gorg, F., (007) Smulatg future Caspa sea level chages usg regoal clmate model outputs, Clm. Dy., 8, pp. 365-379. [7] Radar altmeter data from the NASA/CNES Topex/Posedo ad Jaso- satellte mssos. Tme seres of altmetrc lake level varatos from the USDA Reservor Database at: http://www.pecad.fas.usda.gov/cropexplorer/global_reservor [8] Marc F.P. Berkes, Stochastc Hydrology, Utrecht Uversty, Utrecht, The Netherlads, 007. Page 0