New York Mayor Michael Bloomberg, center, talks about the construction around the site where the World Trade Center once stood to NASA Deputy Administrator Lori Garver, right, and members of the STS-135 crew including commander Chris Ferguson, left, mission specialist Rex Walheim, second right, and pilot Doug Hurley, rear, as they tour the area, Wednesday evening, Aug. 18, 2011, in New York. Photo Credit: (NASA/Paul E. Alers)

New York State

On March 26, New York Mayor Michael Bloomberg declared a drought emergency for the city and four upstate counties in response to the worst drought to hit the eastern United States in nearly 70 years. Restrictions on water use will affect more than 8 million residents of New York. The city's reservoirs, located in the Catskill Mountains, are at 52 percent capacity. One of these, Ashokan Reservoir, is seen in this pair of ASTER images acquired on September 18, 2000 and February 3, 2002. These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet. http://photojournal.jpl.nasa.gov/catalog/PIA03491

Haze over eastern China

The skies over northern China were shrouded with a thick haze in late December, 2013. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite captured this true-color image on December 23. The dense, gray haze obscures almost all the land and much of the coastal waters from view south and east of the Taihang Mountains. Clearer air covers the region north of the mountains, although fingers of haze roll through most river valleys. The cities of Beijing and Hebei, both west of the Bohai Sea are complete enshrouded. By December 24 the smog levels in some area exceeded World Health Organization-recommended levels by 30 times, according to Bloomberg News. The concentration of PM2.5, which are fine air particulates, were reported at 421 micrograms per cubic meter at 2 p.m. near Tiananmen Square in Beijing, while levels were 795 in Xi’an and 740 in Zhengzhou. The World Health Organization (WHO) recommends 24-hour exposure to PM2.5 concentrations no higher than 25 micrograms per cubic meter. While not the sole cause of haze and pollution, the use of coal as a very cheap energy source adds to the problem, particularly north of the Huai River. Prior to 1980, the government policy provided free coal for fuel boilers for all people living north of the Huai River. The widespread use of coal allows people in the north to stay warm in winter, but they have paid a price in air quality. According to Michael Greenstone, a Professor of Environmental Economics at Massachusetts Institute of Technology (MIT), whose research team published a paper on sustained exposure to air pollution on life expectancy in the region, air pollution, as measured by total suspended particulates, was about 55% higher north of the Huai River than south of it, for a difference of around 184 micrograms of particulate matter per cubic meter. The research, published in Proceedings of the National Academy of Sciences in July, 2013, also noted life expectancies were about 5.5 years lower in the north, owing to an increased incidence of cardiorespiratory mortality. Air pollution is an on-going issue for the government of China, and Beijing’s Five-Year Clean Air Action Plan aims to reduce overall particle density by over 25 percent on the PM2.5 scale by 2017, and also takes aim at shutting down all coal-burning plants. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team <a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a> <a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a> Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a> Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a>