The effect of changing Southern Hemisphere winter sea surface temperatures on Southern Annular Mode strength

first_imgWe examine the impact that changes in the winter Southern Hemisphere (SH) meridional sea surface temperature (SST) gradient have on the sign and strength of the SH Annular Mode (SAM). This is undertaken by perturbing either tropical or extra-tropical SSTs in an atmospheric General Circulation Model. Changes in winter tropical SSTs have little direct influence on the SAM but do force a strong wave train in geopotential height across the Southern Ocean. In contrast, changes in winter SSTs in the SH extra-tropics have a profound effect on the SAM: cooler SSTs strengthen the SAM and vice versa. The mechanism involves modifications to the Ferrel cell. As a positive (negative) SAM enhances (reduces) the extra-tropical meridional temperature gradient, these experiments demonstrate a positive feedback mechanism. SAM variability remains unchanged, indicating a shift in the mean, rather than a change in the probability distribution of its positive and negative phaseslast_img read more

Seaborder-13 Exercise Held in Portuguese Waters

first_img View post tag: News by topic This exercise was carried out within the framework of scheduled activities of the ‘5+5 Initiative’ made up of European and African nations from the Western Mediterranean: Portugal, France, Italy, Malta, Spain, Morocco, Mauritania, Libya, Algeria and Tunisia. This year the exercise was planned and organized by Portugal.The domain of ‘Seaborder-13’ was a simulated scenario where a suspect ship, belonging to an international criminal network, was sailing in the Mediterranean Sea and entailed a threat to maritime security for ‘5+5 Initiative’ nations. View post tag: Defense Authorities View post tag: waters October 10, 2013 View post tag: Defence Seaborder-13 Exercise Held in Portuguese Waters Share this article View post tag: Navycenter_img View post tag: held View post tag: Naval View post tag: Exercise View post tag: Portuguese Spanish Minister of Defense, Pedro Morenés accompanied by the Chief of Defense Staff, Admiral Fernando García and the Chief of Naval Staff, Admiral Jaime Muñoz-Delgado, attended the multinational Maritime Security exercise ‘Seaborder-13’organized in Portuguese waters from the 1st to the 3rd of October. Back to overview,Home naval-today Seaborder-13 Exercise Held in Portuguese Waters View post tag: Seaborder-13 ‘Seaborder’ was carried out in two stages. The first one was conducted from the Operations Center in Mauritania with support from Italy and Portugal (days 1 and 2) and consisted in getting acquainted with coordination procedures without using force.The second stage (days 2 and 3) took place in Portimao waters and consisted in a series of drills on communications, maritime interdiction (MIO), search and rescue (SAR) and damage control.Spain has participated with the patrol boat ‘Vigía’, a Security Team, a maritime patrol aircraft (C-235) and a HD-21 helicopter for SAR exercises.5+5 InitiativeThe ‘5+5 Initiative’ was set up in December 2004 when the Ministers of Defense of Algeria, Spain, France, Italy, Libya, Malta, Morocco, Mauritania, Portugal and Tunisia signed a Declaration of Intent to collaborate in maritime security issues in the Western Mediterranean.In 2008 the first ‘Seaborder’ exercise was organized and, since then, it has become one of the most important maritime security exercises of the ‘5+5 Initiative’.[mappress]Press Release, October 10, 2013; Image: Spanish Navylast_img read more