Selective Principal Component Extraction and Reconstruction: A Novel Method for Ground Based Exoplanet Spectroscopy

Context: Infrared spectroscopy of primary and secondary eclipse events probes the composition of exoplanet atmospheres and, using space telescopes, has detected H2O, CH4 and CO2 in three hot Jupiters. However, the available data from space telescopes has limited spectral resolution and does not cover the 2.4 - 5.2 micron spectral region. While large ground based telescopes have the potential to obtain molecular-abundance-grade spectra for many exoplanets, realizing this potential requires retrieving the astrophysical signal in the presence of large Earth-atmospheric and instrument systematic errors. Aims: Here we report a wavelet-assisted, selective principal component extraction method for ground based retrieval of the dayside spectrum of HD 189733b from data containing systematic errors. Methods: The method uses singular value decomposition and extracts those critical points of the Rayleigh quotient which correspond to the planet induced signal. The method does not require prior knowledge of the planet spectrum or the physical mechanisms causing systematic errors. Results: The spectrum obtained with our method is in excellent agreement with space based measurements made with HST and Spitzer (Swain et al. 2009b; Charbonneau et al. 2008) and confirms the recent ground based measurements (Swain et al. 2010) including the strong 3.3 micron emission.Comment: 4 pages, 3 figures; excepted for publication by A&

Vulnerability to Agricultural Drought in Western Orissa: A Case Study of Representative Blocks

The nature of vulnerability to agricultural drought in three study blocks of Bolangir district in western Orissa has been analysed. The indexing and vulnerability profile method have been used for assessing the nature of drought vulnerability, coping capacity and risk. The study has revealed that the three most influential biophysical factors of drought vulnerability are: rainfall variability, drought intensity and shortage of available waterholding capacity of soil and the three most influential socioeconomic factors are: low irrigation development, poor crop insurance coverage and smaller forest area. It is found that while drought risk varies widely across the study blocks and drought vulnerability and physical exposure to drought vary moderately, the coping capacity of study blocks differ marginally. However, the level of coping capacity has been found significantly lower than the level of drought risk and vulnerability in the study blocks.Drought, Drought vulnerability, Composite drought vulnerability index, Physical exposure index, Drought risk index, Agricultural and Food Policy, Q54, Q58, C43, O13,

Latvia's democratic resistance: a forgotten episode from the Second World War

In summer 1943 politicians representing the four main political parties of Latvia's democratic years came together to establish a movement which would both resist the German occupation and prevent the return of the Red Army. They considered the key to re-establishing Latvia as an independent democratic state was to make contact with Britain, and they hoped to do this by a combination of military and diplomatic activity. Once contact with Sweden had been established this Latvian Central Council planned to combine a diplomatic offensive abroad with an insurrection within Latvia. The diplomatic offensive was partly obstructed by the Foreign Office, but that did not prevent the Latvian Central Council working closely with the British Secret Service as it first brought out of Latvia potential members of a Government in Exile, and then began to prepare for an insurrection. Planned to coincide with the arrival of the Red Army and the withdrawal of the Germans, the military wing of the Latvian Central Council intended to seize part of the Courland coast and hold it until British or Swedish forces intervened to prevent them being crushed by the Red Army, thus forcing the Soviets to negotiate about the future status of Latvia. The plans of the Latvian Central Council relied heavily on stories circulating in Sweden that the British were indeed about to intervene in the Baltic, and it is argued here that there was more to this than mere loose talk. The dilemma of whether or not to stage an insurrection was resolved by the Germans, who arrested General Kurelis, the leader of the insurrection and the man designated the interim leader of independent Latvia. The surviving forces of the Latvian Central Council established themselves as an underground army and waited for news from Britain that the time had come to rise. When no such message had come by summer 1945, many underground groups started moves towards a national uprising; to prevent this the Latvian Central Council used its surviving organization to instruct its underground fighters not to take up arms against the Soviets but to wait on diplomacy