You’ve experienced clouds in the lower Earth atmosphere-or troposphere-affecting weather, from those 4 o’clock cumulonimbus clouds in Colorado that left you drenched during a thunderstorm, to the stratus clouds during a foggy visit to the Pacific Northwest. The complex physics of cloud development makes them difficult to predict. Due to this, and the many variables that can alter them, the relationship between clouds and climate is not entirely understood. Tropospheric clouds can play a dual role in climate: they absorb outgoing energy emitted by Earth’s surface to warm us up, and also reflect incoming energy from the Sun back to space and cool us down.
The Sun is the main driver of Earth’s climate, providing 4000 times the amount of energy of all other sources combined. Fortunately, the Sun’s energy is fairly stable, but even small fluctuations can affect Earth’s global and regional climate. Solar variability and other natural influences have historically driven our climate, but today, these have taken a back seat to human-caused effects. In order to understand climate and set appropriate regulatory policies, determining how solar influences contribute to climate change remains a key international priority.
Where do we find life on Earth? Pretty much everywhere, even deep underground. Dr. McCollom will describe life we’ve found in the subsurface biosphere, what we think we’ll find in the future, what it means to be “alive,” and what it might mean for finding life on other planetary bodies.
It’s common to hear these exclamations from those lucky enough to view Noctilucent clouds (night shining clouds) on a summer night near the Arctic Circle. These beautiful clouds occur 50 miles above Earth’s surface, 5 times higher than tropospheric clouds. Also commonly referred to as Polar Mesospheric Clouds (PMCs), they have mystified sky watchers and atmospheric scientists since the late 1800’s. Their unusual occurrence and possible link to climate change has pushed them into the media spotlight over the last decade.
An aurora, a display of light in the sky, is created when energetic charged particles collide with an atmosphere. On Earth, aurorae are typically seen in the polar regions between 65 and 72 degrees north and south latitudes, although occasionally are visible as far south as New Mexico. These brilliant light shows are a dramatic display of the complex interaction between the solar wind and the Earth’s magnetic field, and are fundamental to understanding Earth’s space environment. Dr. Delamere will compare Earth’s aurora to Jupiter’s. Though surprisingly similar in form, Jupiter’s aurorae are driven by mechanisms fundamentally different from Earth’s, leaving researchers to debate exactly how they are created.
Mercury is an incredibly difficult planet to visit, and is the rocky planet we know least about. All that will change this coming March, when MESSENGER, the first spacecraft to visit Mercury in over 30 years, enters into orbit for one year of detailed study. MESSENGER has already had three brief encounters with the planet since launching in 2004, giving us previously unknown information about the Sun’s nearest neighbor. Mercury’s surface may bear a striking resemblance to the Moon’s, but observations of its tenuous atmosphere, global magnetic field, and surface composition suggest a distinctive evolution that makes it completely unique to our solar system. Dr. Holsclaw will talk about recent findings about Mercury, highlighting work done at the University of Colorado on the MESSENGER mission.
We’ve got new eyes staring at the Sun! NASA’s Solar Dynamics Observatory (SDO) launched on February 11, 2010 and is observing the Sun with unprecedented resolution. The solar instruments aboard SDO have 16 Megapixel cameras, more than eight times better resolution than High Definition (HD) TVs. Images and spectra are obtained every 10 seconds, 24/7, and are revealing new results about solar storms. Understanding the Sun is critical to life on Earth since it provides the majority of energy for our environment, and our ever-growing technology is sensitive to large solar storms. Dr. Woods will give an overview of the Sun’s influence on Earth and the new SDO mission, along with dazzling new movies from SDO.