The CAWSES Program and Indian Perspective

Transcription

1 The CAWSES Program and Indian Perspective D. Pallamraju *, S. Gurubaran, and M V Ratnam Scientific Secretary * & Member, CAWSES Science Steering Committee Physical Research Laboratory Ahmedabad India raju@prl.res.in 13 STP meeting Xián, China October 2014

2 Outline Broad overview of CAWSES & CAWSES-India A few sample results Future directions

3 Some perspectives * CAWSES evolved after successful SCOSTEP programs such as: IMS, SMY, MAP, STEP, S-RAMP, EPIC, PSMOS, ISCS CAWSES in a way coupled ALL the above programs!! Emphasis was on both vertical and horizontal coupling CAWSES Newsletters (both Phases 1 & 2) were very well received Several nations had successful CAWSES programs, e.g., Brazil, Canada, China, Germany, India, Japan, US * List incomplete

4 CAWSES-Phase I ( ) 4 science themes Solar Influence on Climate Space Weather: Science and Applications Atmospheric Coupling Processes Space Climate

5 CAWSES-Phase II ( ) 4 science questions What are the solar influences on the Earth s climate? How will the geospace respond to an altered climate? How does short term variability affect the geospace environment? What is the geospace response to variable waves from the lower atmosphere?

6 Some salient features of CAWSES- Phases I & II ( ) * Both CAWSES Phases I & II had involved obs. campaigns Several workshops were conducted A successful Virtual Poster Session was also held Several CAWSES Science Sessions were organized CAWSES Special issues EPS, JASTP, etc. 9 CAWSES comic books were printed (translated into several languages internationally) Sustained Capacity building efforts led by SCOSTEP * List incomplete

7 CAWSES-India (both Phase I and II) -- supported by the Indian Space Research Organization (ISRO)

8 CAWSES-India Phase II ( ) National Scientific Steering Committee reconstituted A National-level Workshop held during July 9-11, themes identified (based on the strengths within India) 1. Solar Influence on Climate 2. Space Weather and Climate: Science and Applications 3. Atmospheric Coupling Processes

9 A few sample results..

10 IPS of Solar wind with radio sources from Ooty Radio Telescope 3-D Density Reconstruction The left fig shows an ecliptic cut through the 3-D Ooty IPS density reconstruction and the right fig show a meridional cut (from East of the Sun-Earth line) of the same; both with the Earth on the right-hand side and it s orbit shown in each case Courtesy: P. K. Manoharan

11 Using LASCO and IPS data it was found that: 1.the CME speeds are slower at 1 AU than the initial speeds 2.Due to the aero-dynamic drag between the CME and the solar wind the speed of the CME tends to equalize to that of the background solar wind - Such finding are critical in Space Weather modeling studies In-situ speed of the CME at 1 AU wrt travel time of the CME between the LASCO field of view and 1 AU. Manoharan and Rahman, 2011, JASTP

12 Effect of Solar flare on Neutral Optical Dayglow Emissions X-Ray Flux factor > 300 EUV Flux ~60 % EEJ ~143 % Dagylow ~50 %

13 Universal Time DMSP F15 satellite measured Electron Flux Short duration but large spatial-scale Phenomena Enhancement in the redline dayglow caused due to increase in the photoelectron flux Das et al., JGR 2010

14 Prediction of magnetic substorms using a state space model Dawn-dusk electric field VBz is taken as input and AL is the output 28 Aug 02 Sep Nov 2004 Dst varied between: nT, All those cases have been predicted well with this method Sep Mar 03 Apr 2001 Unnikrishnan, 2012 JASTP

15 h F (km) Pre-midnight rise of ionospheric layer during summer months in solar minimum Vertical drift (m/s) 60 o 120 o Long. sector C/NOFS * Model Local Time (Hrs.) Local Time (Hrs.) * Communications/Navigation Outage Forcasting System satellite (NASA) Ionospheric height rise is important for generation of plasma irregularities during nighttime. This occurs during evening hours in the solar maximum and in the pre-midnight hours in the solar minimum. However, solar minimum behavior has not been understood so far. Combining radar and satellite measurements, it is revealed that semi-diurnal tide plays an important role over Indian sector that causes the observed pre-midnight height rise. Chakrabarty et al., JATP, 2014

16 C- Shaped structure during Space Weather event Evidence for presence of Shear during the C-shaped plume structure has been obtained Indication obtained by optical measurements at two different wavelengths. Emissions originate from ~ 250 and 300 km Sekar et al. 2012, JASTP

17 Ionospheric data of - 14 stations - 3 solar cycles (0-45 o N MLAT) is considered & 2 nd order poly. coeff. obtained Comparison Made between SD fof2 and IRI predicted fof2 SD model shows better results when compared with IRI. Ionospheric Prediction Model The Second-Degree model, based on monthly median values, is useful for providing long-term predictions for HF communication applications. Dabas et al. 2008; JGR

18 Effect of poleward gradient in electron density on SBAS applications Problems likely to be faced in SBAS when estimating an optimum grid size around the crest of the EIA are highlighted. Steeper gradient of the EIA poleward of the northern crest as compared with the equatorward side poses problems. Paul et al., 2011, JASTP

19 Grid chosen is 5 o x 5 o However, 1 3 TECU error likely in 0.7 o x 0.7 o grid Necessary corrections need to be incorporated

20 Mesosphere Lower Thermosphere Interactions Existence of quasi-16 day periodicity in the occurrence of CEJ along with the SSW events were shown using the equatorial magnetic, optical and neutral wind datasets Indications were also shown that the zonal winds turn eastward and move towards high-latitudes prior to the occurrence of SSW events. Vineeth et al., 2007 GRL; 2009 AG

21 Vertical & latitudinal coupling of atmospheres During strong SSW events (high latitude rise in temperature), the EEJ and the TEC (at low-latitudes) show in phase oscillations of Quasi 16-day power Laskar et al., 2014 EPS

22 Daytime waves in the MLT region investigated through balloon-borne measurements - Balloon-borne Investigations of Regional-atmospheric Dynamics (BIRD) carried out on 8 March 2010 from Hyderabad, India. BIRD: Joint Indo-US expt. ~ km scale sizes Pallamraju et al., 2014; JGR

23 CAWSES Solar eclipse campaign 11 sounding rockets fired during 15 Jan 2010 solar eclipse campaign. Reduction in electric field during solar lower alt Alteration of winds noticed Reduction in the TEC Enhancement in the ionospheric F-layer height Enhancement in the occurrence frequency of Tweeks Several Ozonosonde/GPS sondes launched during 22 July 2009 (Total SE) and 15 Jan 2010 (Annular SE) over India Coordinated ground based network with optical and radio measurements was carried out

24 More results have been tabulated in: An overview of the CAWSES-India program by Rao et al., 2012; JASTP A compendium brought out in the form of proceedings of a national workshop conducted in NARL Compendium of the results obtained during the Solar eclipse campaign brought out. JASTP Special issue on CAWSES-India Phase II Program in 2014 Tropical Tropopause Dynamics Campaign Ratnam et al., 2014 * List incomplete

25 Next steps ISRO has formulated a new program called STARP (Solar Terrestrial Atmospheric Research Program) VarSITI Future Earth 1 st meeting planned in next month

26 Summary Similar to the CAWSES program internationally, CAWSES-India program has been a great success (> 130+ publishes articles (Ph II) Several ground-based, balloon-based rocket- & satellite-borne experiments have been carried out in the recent past with active participation of CAWSES scientists New results have emerged in terms of atmospheric coupling processes and in the space weather interactions New program called, STARP has been initiated.

27 Acknowledgement CAWSES/SCOSTEP resources ISRO Dept. of Space, Gov. of India

28 Thank you for your attention