The University of Arizona

Let’s Talk Science

All “Let’s Talk Science!” lectures are included with the price of tour admission. For more information about the lectures, or for tour prices and hours of operation, please call 520.838.6200. All talks begin at 12:00 PM.

Spring 2010 Lecture Series: Extreme Water!

March 20, 2010
Floods, Climate and “Cuisinart” Hydrology: A Recipe for Disaster?

Katie Hirschboeck
Chair, Global Change Graduate Interdisciplinary Program
Associate Professor of Climatology, Laboratory of Tree-Ring Research
University of Arizona

What causes flooding in the Desert Southwest?  Why do we need to worry about floods in Arizona when our rivers are dry most of the time?  What is a “100-year flood”?  What can we learn from large floods of the past?  Will climate change make floods more extreme?  These and many other questions about the phenomenon of flooding will be addressed in a presentation covering the flood hydroclimatology of the rivers and streams of Arizona. 

March 27, 2010
Six Degrees of Separation: Can We Live with a World much Warmer than Today?

Diana Liverman
Co-Director, Institute of the Environment
University of Arizona

Diana Liverman will talk about her research on the impacts of climate change and the choices we face about responding to such changes in the southwest and globally. She is an expert on climate and food security and on how societies can become less vulnerable to climate change.

April 3, 2010
Extreme Variability: Southwest Climate

Melanie Lenart
University of Arizona researcher, instructor
Author of Life in the Hothouse: How a Living Planet Survives Climate Change

Arizona often goes from one extreme to the other, as this wet winter in the midst of drought reminds us. These kinds of ups and downs are likely to continue as the planet warms, given the competing influences on rainfall in the Southwest. Meanwhile, temperatures are expected to become even more extreme. This talk will draw from past climates, present understanding and future projections to ponder the coming changes—as well as a few ideas about what we can do about it.

 

Past Lectures

March 13, 2010
Tree Rings and Colorado River Drought: A Message from the Past with Implications for the Future

Connie Woodhouse
Associate Professor
School of Geography and Regional Development
University of Arizona


The gage record for the Colorado River is barely 100 years long. While that may seem like a long span of time, the record contains just three major droughts. Are these droughts representative of the range of droughts that are possible? Should we expect more severe droughts in the future? Tree rings allow us to reconstruct a history of past river flow, going back over 12 centuries. The reconstruction of Colorado River flow shows that droughts much more severe have occurred in the past, under natural climate variability alone. In this presentation, I will show how we develop these reconstructions from tree rings, describe the droughts of the medieval period, and discuss how information from the past is relevant to the future.

March 6, 2010
Cool waters—The Hydrology of the Perennial Rivers of Arizona

Thomas Meixner
Associate Professor
Hydrology and Water Resources Department
University of Arizona

Water is scarce in Arizona so the few remaining perennial waters are prized resources for society and for ecosystems.  I will talk about my research on the sources of water that sustain different rivers in the desert lands of Arizona and how these rivers are influenced and studied by humans.

February 27, 2010
Water Sustainability Challenges in Arizona

Sharon Megdal
Director
Water Resources Research Center
University of Arizona

Learn about how Arizona’s 1980 water law was designed to stop groundwater overdraft in parts of the state while not regulating water use in other parts. What have we achieved and what challenges remain after 30 years? What issues must we address in order to achieve sustainable water management in Arizona? The presentation is designed to assist you in deciding how full our state's water glass is! 
 
Free background reading available: The Layperson’s Guide to Arizona Water

February 13, 2010
The Search for Life in the Driest Desert on Earth—The Atacama Desert, Chile

Raina Maier
Professor
Soil, Water, and Environmental Science Department
University of Arizona

Julia Neilson
Principal Research Specialist
Soil, Water, and Environmental Science Department
University of Arizona

Is there a limit to life on earth? There are regions of the Atacama Desert where no precipitation has been recorded for as long as humans have kept records of rainfall. Some scientists claim to have found the dry limit of microbial life in these hyperarid regions.  This talk will describe the search for signs of microbial life in the absolute core of the Atacama Desert and explore whether the biosignatures found give us clues to past precipitation history. The Atacama is considered an analog for Mars, thus researchers hope that the signs of life found in this desert could guide us in our search for life on other planets.

February 6, 2010
Unquenchable: America’s Water Crisis and What To Do About It

Robert Glennon
Morris K. Udall Professor of Law and Public Policy
James E. Rogers College of Law
University of Arizona

America's self-inflicted water crisis is coming.

Our water woes will get worse before they get better because we are slow to change our ways, and because water is the overlooked resource. It’s happening again: Washington's love affair with biofuels will turn to heartbreak once America realizes that thousands of gallons of water are required to produce one gallon of fuel.  Glennon tells how a celebrated, new ethanol plant in Minnesota—The Land of 10,000 Lakes!—is already sucking local wells dry.

Glennon argues that we cannot engineer our way out of the problem with the usual fixes or the zany—but very real—schemes to tow icebergs from Alaska or divert the Mississippi River to Nevada. America must make hard choices—and Glennon's answer is a provocative market-based system that values water as a commodity and a fundamental human right.

December 5, 2009
The Air We Breathe

Eric Betterton
Professor and Head
University of Arizona Department of Atmospheric Sciences Director
University of Arizona Institute of Atmospheric Physics

Humans can live for a week without food, several days without water, but just a few minutes without air. Find out about the swirling ocean of air we often take for granted yet cannot live without. Learn what we mean by "good" and "bad" ozone; how colorless air molecules turn the sky blue; why cloud droplets are white; and other fascinating facts about the air we breathe.

November 28, 2009
Using Solar Power When It Rains

Alexander Cronin
Associate Professor
University of Arizona Departments of Physics and Optical Sciences

Cronin will present data from photovoltaic test yards. Annual energy yields, system efficiencies, reliability, degradation rates, and costs will be reported. Solar power is intermittent due to clouds and nighttime. Therefore energy storage or a Smart Grid will be needed if solar power is to provide more than 2% of the electricity used in Tucson. I will defend this claim and share some proposals for integrating megawatt-scale batteries with photovoltaic fields.

November 21, 2009
What do Africa, the Caribbean, Hurricanes and the Southwest all have in common?

Yolande Serra
Research Associate Professor
University of Arizona Institute of Atmospheric Physics

Serra will talk about tropical "easterly waves" or disturbances in the easterly winds that flow from Africa across the Atlantic and into the Gulf of Mexico-Caribbean region. These disturbances are the most common precursor to hurricanes that form both in the western Atlantic / Gulf of Mexico / Caribbean and the eastern Pacific. They are also what we generally mean when we talk about a "tropical storm track". Serra will talk about how we think these disturbances affect the weather in Arizona during the monsoon and how this link is affected by El Nino vs La Nina conditions. She will also talk about what may happen to this link between the tropics and the Southwest in a warmer climate.

November 14, 2009
The Anatomy of Lightning Flashes: What They Look Like and Why We Care

Ken Cummins
Research Professor
University of Arizona Institute of Atmospheric Physics

Lightning is both beautiful and dangerous. The bright imagery in the sky that entertains us is a direct threat to air and ground-based operations, and is a reflection of other destructive forces associated with thunderstorms and severe weather. Cloud-to-ground (CG) lightning is the single largest natural cause of forest fires and of disturbances to electric power transmission and distribution systems. The characteristics of CG lighting will be preseted in terms of its luminus and electromagnetic behavior at timescales ranging from normal human perception to microsecond-scale characteristics. Examples of lightning's impact on society will also be presented.

November 7, 2009
El Niño and Southern Arizona: Messing with the Monsoon

Chuck George
Chief Meteorologist
KOLD News 13

The cyclical oceanic pattern was likely the primary reason Monsoon '09 was such a bust. We'll look back at a lackluster summer and forward to the winter rainy season.

October 31, 2009
Who Benefits from Evaporation from the Southwest?

Francina Dominguez
Assistant Professor
University of Arizona Departments of Atmospheric Sciences & Hydrology and Water Resources

This talk presents a simple method for tracking atmospheric water, from the time it evaporates from a region to the time it falls as precipitation in a downwind area. In this way, we show how different ecosystems can be linked through atmospheric water vapor paths. Specifically we will talk about the North American Monsoon region - where does our water come from and where does it go.

October 24, 2009
30% Chance of Storms Again Today!? A New Method to Forecast Arizona Summer Thunderstorms

Mike Leuthold
Lecturer
University of Arizona Institute of Atmospheric Physics

Forecasting summer thunderstorms are notoriously difficult and frustrating for meteorologists. The Atmospheric Sciences department at the University of Arizona has developed a new technique to better forecast these storms by using a high-resolution regional weather model. We'll look at why it's so hard to forecast these storms and explore how the regional weather model can improve summer thunderstorm forecasts.

October 17, 2009
Adventures with Hurricanes

Elizabeth Ritchie
Associate Professor
University of Arizona Departments of Atmospheric Sciences & Electrical and Computer Engineering

Born over the warm moist tropical oceans, packing winds over 33 m/s (74 mph), and reaching diameters of over 1000 km, the hurricane is the most intense weather system on Earth. Although they have been studied extensively throughout the twentieth century, there is surprisingly little quantitative knowledge as to how hurricanes develop and progress through their life cycle. The major problems that inhibit progress in this area are the chronically sparse data over the tropical oceans and the difficulties in separating cause and effect in these complex systems with important, nonlinear, interacting processes occurring on several time and spatial scales. In this talk we will look at the complex life-cycle of the hurricane. We will investigate their many forms in the tropical basins around the world and focus in on the challenges that eastern Pacific hurricanes pose for the semi-arid southwest U.S.

October 10, 2009
The North American Monsoon: It's What Makes Summer Weather Interesting in Arizona!

Christopher L. Castro
Assistant Professor
University of Arizona Department of Atmospheric Sciences

This program is designed to give participants a broad conceptual understanding of the summer monsoon in Arizona. It consists of a few simple laboratory experiments to demonstrate convection and cloud formation, a lecture on the monsoon, and a monsoon forecast discussion. A handout on the monsoon prepared by the National Weather Service will also be provided.

Christopher L. Castro became a faculty member in the Department of Atmospheric Sciences at the University of Arizona in August 2006. His doctoral and postdoctoral work at the Department of Atmospheric Science at Colorado State University applied a regional atmospheric model to the investigation of North American summer climate. Current research within his group at the University of Arizona focuses principally on physical understanding and prediction of summer climate in North America through regional atmospheric modeling and analysis of observations.