The temporal evolution of electron distributions and associated wave activity following substorm injections in the inner magnetosphere

first_imgThe temporal evolution of electron distributions and associated wave activity following substorm injections in the inner magnetosphere are investigated using data from the CRRES satellite. Equatorial electron distributions and concomitant wave spectra outside the plasmapause on the nightside of the Earth are studied as a function of time since injection determined from the auroral-electrojet index (AE). The electron cyclotron harmonic (ECH) wave amplitudes are shown to be very sensitive to small modeling errors in the location of the magnetic equator. They are best understood at the ECH equator, defined by the local, maximum in the ECH wave activity in the vicinity of the nominal magnetic equator, suggesting that the ECH equator is a better measure of the location of the true equator. Strong ECH and whistler mode wave amplitudes are associated with the injected distributions and at the ECH equator, in the region 6.0 less than or equal to L < 7.0, exponential fits reveal wave amplitude decay time constants of 6.3+/-1.2 and 4.6+/-0.7 hours, respectively. Pancake electron distributions are seen to develop from injected distributions that are nearly isotropic in velocity space and, in this region, are seen to form on a similar timescale of approximately 4 hours suggesting that both wave types are involved in their production. The timescale for pancake production and wave decay is comparable with the average time interval between substorm events so that the wave-particle interactions are almost continually present in this region leading to a continual supply of electrons to power the diffuse aurora. In the region 3.8 less than or equal to L < 6.0 the timescale for wave decay at the ECH equator is 2.3 +/- 0.6 and 1.1 +/- 0.2 hours for ECH waves and whistler mode waves respectively, although the pancakes in this region show no clear evolution as a function of time.last_img read more

Seeds of violence in climate change

first_imgThis is second in a series of stories about Harvard’s engagement in Latin America.When Nathan Black considers the potential global consequences of climate change, one thing he sees is war.Black, the French Environmental Fellow at the Harvard University Center for the Environment, is spending two years investigating the connection between changing agricultural conditions — specifically the supply of agricultural land — and civil war.He is examining the cases of two nations, Haiti and Mexico, where shifts in the supply of agricultural land sparked violent conflict. He is also looking at Uruguay, which avoided conflict despite similar conditions in the late 1980s and early 1990s, to understand how violence was averted.“What I’m looking at is, ‘What did Uruguay do that Haiti and Mexico failed to do?’” Black said. “What is the playbook?”Black, who earned a bachelor’s degree from Rice University and a doctorate from the Massachusetts Institute of Technology, became interested in conflict as a field of study as an undergraduate, but focused on interstate conflict. When he entered MIT for his doctoral work, a colleague’s investigation of civil wars piqued his curiosity.Far less has been written about civil conflict than clashing nations, he said, which leaves many interesting questions still to be answered. His doctoral dissertation was about developing civil conflicts spilling across borders. He also began thinking about his current topic, and in 2010 published an article on how changes in the supply of arable land can fuel civil war. Black was a pre-doctoral fellow at Harvard’s Belfer Center for Science and International Affairs before graduating from MIT in 2012.“I think my own research suggests that on average, as arable land supplies decrease due to climate change, we should see more violent civil conflicts,” he said.Kenneth Oye, an associate professor at MIT and director of its Center for International Studies, said Black’s work is unusual in that it not only examines a potential problem stemming from climate change, but also seeks practical approaches to resolve it.“He’s an unusual guy because his commitment to tackling central issues that are of policy relevance has been with him from the beginning,” Oye said.Climate is not a clear factor in the cases Black is studying, but lessons on the consequences of changes to the land supply — whatever the source — should still apply. In Haiti, poor agricultural practices degraded land, a situation exacerbated by corruption that diverted needed aid. In Mexico’s Chiapas region, government inaction on reform left land-poor peasants to watch elites buy up more land.The rising temperatures and changing rainfall patterns expected by scientists in coming decades could accelerate desertification and take land that is currently used for agriculture — particularly in Africa and Latin America — out of production. Shifting precipitation patterns could also mean too much rain in some places, leading to crop failures.“Some places will benefit from climate change. Unfortunately, most places [negatively] affected by climate change are also susceptible to violent civil conflict,” Black said.The loss of livelihood from the land can prove ruinous for subsistence farmers and, by extension, the government, Black said. His studies of Haiti during the dictatorial reign of Jean-Claude Duvalier in the 1970s and 1980s showed that the degradation of agricultural land stemmed from widespread cutting of trees for firewood, coupled with a lack of improvements in irrigation and crop variety. The agricultural decline led to the migration of many young men with little money and fewer prospects to the cities, all too ready to join the unrest that followed Duvalier’s exit in 1986.Black traveled to Haiti in January and interviewed two of Duvalier’s agriculture ministers, the current director of the land reform effort, and a group of peasant organizers. He also sought to interview Duvalier himself, who returned to Haiti in 2011 after 15 years in exile, but received no response.Black is about halfway through his research, which he plans to publish in a book. Before that, though, he has work to complete in Chiapas, where land grabs by politically connected elites fed the Zapatista movement of the 1990s. The movement, which burst forth as an armed struggle in 1994 and was put down by the Mexican military, has since embraced nonviolent means of change.Black has completed much of the background work on Uruguay and plans to visit this month to speak with two former presidents, Julio Sanguinetti, who served from 1985 until 1990 and again from 1995 until 2000, and Jorge Batlle Ibáñez, who served from 2000 to 2005. Also on his list are a former vice president and a former agriculture minister.The problems in Uruguay in the 1970s and 1980s were somewhat different than those in Haiti and Mexico. Much of its population was already urbanized, so the danger was that agriculture-related shocks would send the economy into a tailspin, creating a pool of potential recruits for rebel groups.The country’s agricultural economy is dominated by ranching, with beef its largest export. With the market flagging, leaders took two big steps to improve it, initiating reforms that began in the 1960s and stretched through the 1980s, Black said.First, they invested in a vaccine for foot and mouth disease, which allowed the country to eradicate the disease in 1993 and again when it recurred in 2000. By eradicating foot and mouth, the nation’s beef exports gained or maintained access to U.S. and European markets, larger and with steadier demand than South American nations.The second thing the government did was invest in seeds for better pasturage, which increased the number of cattle that could be grazed on an acre of land.So far, Black said, the main lesson to emerge from his research is that governments should bypass quick fixes and instead invest in long-term improvements in the agriculture sector, making it more resilient.“I hope the book will be a call to action to developing state governments and the developed nations that support them to make serious and sustained investment in the agriculture sector,” Black said. “You can’t just flip a switch and change agricultural technology.”last_img read more

How to host a great Dönerstag event

first_imgName tags are great for any event, but make a game out of it by having your guests try to match the geocaching username to the person. You never know just how many stories are behind a name! Everyone loves prizes! Award prizes for the best costume or keep it simple with a random raffle drawing for all attendees! Not your average logbook: create a logbook for your event in the shape of a kebab or to look like the striped Döner paper wrapper! SharePrint RelatedWhere in the world is Signal? (Hint: Grüße aus Deutschland!)February 24, 2017In “News”Dönerstag celebrations from around the worldApril 24, 2017In “Community”How to organize a great Dönerstag eventMarch 14, 2017In “Español” Variations of kebab are all around the world. For a DIY project, create a Pin the Kebab on the Country gameboard! In 2017, we’re celebrating geocaching around the world and as Signal prepares to visit Germany for Dönerstag, we’re sharing a guide on how to host an awesome Dönerstag event!Last year, there were over 35,000 geocaching events around the globe. Events are a chance to meet fellow geocachers, swap trackables, learn about the game, share experiences, and have fun! Read on to learn how to celebrate Dönerstag wherever you are.Remember, you can earn the first-ever Dönerstag souvenir by attending a geocaching event on April 13, 2017!Get CreativeDöner kebabs, made traditionally of roasted meat cooked on a vertical spit, gained popularity in Germany in the 1980s. However, you don’t have to be in Germany to enjoy Döner kebab!Kebab goes by many names, such as shawarma or gyros, and vary from region to region. Check out this list of similar dishes from around the world!Make it funMusic, games, and prizes, oh my! Preparing a few activities in advance is a great way to break the ice and keep guests having fun! We’ve gathered a few ideas to make your Dönerstag event an international success!Set the tone by playing German music, after all Dönerstag is a German geocaching holiday! Want to take things up a notch? A spicy Döner sauce eating contest might be just what you’re looking for. Caution: play this game at your own risk!Don’t forgetYou can host Event Caches anywhere available to the public — such as a restaurant or park. But be sure to find a place that has enough space and let the venue know you’re coming. Geocaching events need to be submitted at least two weeks before the event date. Submit your Dönerstag events for review no later than March 30, 2017. Once your event has been published, share the event listing with your local geocaching organization and on social media.Most importantly though, have fun! These awesome Dönerstag party pointers will surely make your event one to remember. Can we be invited?Share with your Friends:Morelast_img read more

9 Tips for Shooting in Cold Weather

first_imgKeep your equipment safe when shooting in cold weather.Winter is upon us. So, in light of the recent polar vortex, we’ve rounded up our best tips for cold weather photo and video shoots.1. Avoid ‘Cold Soaking’“Cold Soaking” is allowing your camera to become as cold as the environment around you…and you want to avoid this. Allowing your camera to reach sub-zero temperatures is a recipe for disaster as most cameras aren’t created to withstand subzero temperatures. Keep your camera in it’s case/bag until it’s time to shoot. In extreme temperature scenarios it may be beneficial to include additional insulation in your camera bag.2. Carbon Fiber TripodIt doesn’t take a rocket scientist to figure out that a cold metal tripod in cold weather is a bad idea. Instead of freezing your fingers off try using a carbon fiber tripod. Carbon fiber tripds are great for shooting in extreme temperatures. They’re also extremely lightweight when compared to their metal counterparts.3. Bring Extra BatteriesBatteries drain faster in cold weather. So next time you have to shoot in extreme cold make sure you pack 2 to 3 times your normal supply of batteries.4. Use Hand WarmersSmall hand warmers are a lifesaver in cold weather and they can serve a variety of other purposes. For example, a small hand warmer can be placed in your camera bag to regulate the temperature.5. Bring ND FiltersSnowy is bright even in overcast weather. For this reason you should bring your ND filters along. ND filters cut out incoming light and allow you to use a wider aperture even in bright conditions. This is really important if you are wanting to get a shallow depth of field.6. Gradually Go from Cold to WarmProblems may arise if you quickly go from a cold environment to a warm one – condensation can form on your camera and lens. It’s best to allow your camera slowly to adjust to room temperature. One trick is to keep your lenses in Ziplock freezer bags, allowing them to acclimate to the temperature change before opening. Adding silica gel packs in the baggie can help cut help alleviate any humidity.If condensation gets inside the camera or lens body it can permanently damage the hardware. In these extreme scenarios it is best to let the camera completely dry out before attempting to use it again.7. DehumidifiersOne way you can significantly cut back on condensation is to put a dehumidifying pack in your camera bag. Just as you might imagine, these packs are designed to absorb moisture making your camera less likely to experience damage as a result of condensation.Lens cap manufacture BRNO make dehumidifying lens caps that have silica gel built-in. If you’re going to be doing a lot of outdoor cold-weather photography or filmmaking it might be worth it to get a few.8. Get a Coated LensMost modern day lenses come with special coatings that allow them to withstand the elements. This is especially important when shooting in cold weather as it is easy to get things like snow and condensation on the lens. If you’re considering renting a lens check out if it has a specialty coating on it.9. Winter-Proof CasesThere are a few winter-proofing camera cases that you can buy to protect your camera gear, including the Camera Duck which goes for about $130 on B&H. Camera Duck also sells large warmers designed to fit over their weather covers.Even if you don’t want to spend the money on a winter cover, a waterproof case is a worthwhile investment.Have any other tips for shooting in cold weather? Share in the comments below.last_img read more

Deshmukh defeats Vengsarkar to become new MCA president

first_imgBacked by Sharad Pawar, Union Minister Vilasrao Deshmukh on Friday pipped former India skipper Dilip Vengsarkar in a fiercely fought contest to become the new president of the Mumbai Cricket Association.Deshmukh defeated Vengsarkar by 181 votes to 136 to emerge triumphant in the biennial elections. Both Desmukh and Vengsarkar were vice-presidents in the outgoing committee which was headed by Pawar.Pawar had become ineligible to contest the polls as per a clause in the MCA’s constitution following a change of his permanent residence status from Mumbai to Baramati.Pawar’s panel members – Prof Ratnakar Shetty and Ravi Savant – were elected as vice-president and treasurer respectively while D Y Patil Sports Academy’s chairman Vijay Patil, who contested as an independent, became the other vice-president.Two other members of the Pawar panel – Dr P V Shetty and Nitin Dalal – also emerged victorious to become the two new joint secretaries.Deshmukh, a former state Chief Minister, followed the footsteps of Manohar Joshi (1992-2001) and Pawar (2001-2011) to become the 13th MCA president since it was founded in 1930-31.– With PTI inputslast_img read more

President Pranab Mukherjee to Modi govt: Bring economy back on track

first_imgPresident Pranab Mukherjee on Monday addressed the joint sitting of Parliament, elaborating on the agendas of the new government. While saying that poverty had no religion, creed and region, he informed the house about government’s commitment to poverty alleviation.Terming the current economic situation as “extremely difficult”, President Pranab Mukherjee today expressed the government’s commitment to put India back on high growth path, while containing inflation and making tax regime non-adversarial.”…putting the Indian economy back on track is paramount for my government. We will work together to usher our economy into high growth path, rein in inflation, reignite the investment cycle, accelerate job creation and restore the confidence of domestic as well as international community in our economy,” he said.The President in his address to the joint sitting of Parliament unveiled the policies and priorities of the BJP – led NDA government which assumed power last month after elections to the 16th Lok Sabha.Prime Minister Narendra Modi with President Pranab MukherjeeThe economy, Mukherjee said is “passing through an extremely difficult phase. For the two consecutive years, our GDP growth has been less than 5 per cent. Tax collection has declined. Inflation continues to be an at unacceptable level”.Referring to the high food inflation, he said the new government will give “top most priority” to contain it.The government, he added, will take effective steps to prevent hoarding and black marketing and reform the public distribution system, incorporating best practices from the states.The President further said the government is alert about the possibility of a subnormal monsoon this year and is in the process of preparing contingency plan to deal with the situation. advertisementThe government announced Monday that it will liberalise foreign equity in defence production and will also encourage private investment in defence.”Government to encourage private investments in defence production,” President Pranab Mukherjee said. (Must read: Full text of President Pranab Mukherjee’s speech ) He added that the government will also liberalise FDI (foreign direct investment) in defence production.”With available human resources, India can emerge as global platform for defence,” he said.Mukherjee also said the armed forces will be modernised and manpower shortages addressed on priority.A national maritime authority will also be set up.President Pranab Mukherjee addresses Parliament’s joint session: Highlights- It’s a matter of great satisfaction that general elections were smooth and largely peaceful.- This has been an election of hope.- A party has got absolute majority after almost 30 years.- My govt will function with the mantra of “minimum government, maximum governance”.- I congratulate fellow citizens for voting for stability and development.- The greatest challenge before us is to end the curse of poverty in India.- My govt will take steps to curb hoarding and black marketing.- My govt is alerted to a sub-normal monsoon this year, contingency plans are being made.- My govt is committed to improving quality of life in villages through empowered panchayati raj system.- We will not settle for only poverty alleviation, we are aiming for poverty elimination.- Each drop of water is precious, my govt is committed to giving high priority to water security.- My govt will launch national sports search system; sports will be made integral part of school curriculum.- Swachch Bharat Mission to be launched.- The govt will set up IITs and IIMs in every state.- National Madarssa modernisation programme will be initiated.- ‘Beti Bachao and Beti Padhao’ mass programmes to be launched.- Govt will formulate a new health policy and roll out a national health insurance mission.- Govt will have zero tolerance towards violence against women.- It’s govt’s commitment to have 33 per cent reservation for women in Parliament.- Issue of infiltration in the North-East will be tackled on priority.- Efforts will be made to ensure that Kashmiri Pandits return to their homeland.- National e-governance plan to be launched, Wi-Fi zones to be provided in critical public areas in the next 5 years.- Social media will be used for participatory governance.- Tax regime will be made non-adversarial and investment friendly.- Govt will launch a diamond quadrilateral project of high-speed trains.- India can emerge as a global platform for defence. My govt will address manpower shortage on priority in the defence services.last_img read more