Do Hurricanes Impact the Southwest? Sept. 7, 2011 Luckily, we’re pretty landlocked here in the Southwest, so unlike the East Coast, we don’t have to worry about hurricanes causing massive flooding and downing trees and power lines. Or do we? As it turns out, hurricanes and tropical storms in the eastern Pacific play a major role in our moisture budget and rainfall extremes. (Read More) Read more
Communicating CPC’s Seasonal Forecasts: It’s Complicated Sept. 3, 2011 Many of us have seen the seasonal outlooks issued by the Climate Prediction Center (CPC) forecasters. These predictions are extremely important to those who have to make choices based on temperature and precipitation, such as natural resource managers, farmers, and ranchers. But there is a lot of information in the shading and numbers on these maps, and it’s not always clear what it all means. (Read More) Read more
The North American (paleo)monsoon: What can the last few thousand years tell us about our future? Aug. 25, 2011 The monsoon is in full swing here in Tucson! Unfortunately, compared to the last two summers, this monsoon is looking somewhat better, but not by much (see recent CLIMAS report). This begs the question: is there any chance we could depend on the monsoon to help alleviate some winter water shortages in the future as global climate changes? (Read More) Read more
Monsoon Extremes, Past and Future June 13, 2011 We’re all itching to know if the monsoon will deliver this year, especially with the record wildfires, the widespread drought, and the closure of national forests across Arizona and New Mexico. Since our records of rainfall only go back to 1900, it’s hard to tell if the monsoon could get even stronger, or weaker, or if there could be periods of persistently strong or weak monsoons (e.g., ten years in a row of weak monsoons). To get at this information requires longer records of monsoon variability. Luckily, there are many archives of climate in the natural world. (Read More) Read more
Southwestern Trees Hold the History—and Future?—of El Niño May 10, 2011 The impact of tropical Pacific ocean temperatures on the hydroclimate of the Southwest is profound: on timescales of 2-8 years, El Niño and La Niña events influence the amount of winter precipitation we receive. Trees living across the Southwest region record these changes in moisture in the width of their rings, providing us with a history of precipitation going back thousands of years or longer in some places. (Read More) Read more
Will Climate Change Impact Nuclear Energy in the Southwest? April 8, 2011 Author: Britain Eakin In the process of generating nuclear-based electricity, large amounts of cool water are needed to maintain safe temperatures in the reactors. This is why the overwhelming majority of nuclear power plants are located adjacent to bodies of water; they divert water from these sources for cooling, and then release it back into the same sources. Climate change has the potential to significantly impact water availability and water temperatures, especially here in the Southwest; this raises the question of whether nuclear energy production could be affected by climate change as well. (Read More) Read more
Managing Changing Landscapes – We Have the Tools to Respond! Feb. 14, 2011 Author: Marcos Robles A slew of articles in the scientific literature and popular media report how the Southwest is one of the epicenters for climate change impacts in North America. Over the last half century, warming across the region has contributed to larger wildfires, widespread piñon tree mortality, declining snow packs and earlier stream flows. While these reports express the urgency of responding to climate change, they also raise many questions. (Read More) Read more
Megadrought: Is the Past a Key to Our Future? Dec. 4, 2010 Megadroughts, defined as droughts far more severe than anything we have experienced in the 20th century, have occurred numerous times across the Southwest. Are we due for another? As outlined in Jonathan Overpeck’s October post “What’s Ahead for the Climate of the Southwest?” changes in drought and aridity are forthcoming. Warmer regional and global temperatures are driving more evaporation and shifting the position of winter storm systems away from the Southwest. (Read More) Read more
Western Fire on the Rise Oct. 29, 2010 Author: Laura Marshall It’s become a regular thing to turn on the news during the hot months of the year, and see images of wind-whipped flames devouring a California subdivision or a forested mountainside. In the last decade, fires in the West have burned much larger areas than previously. This phenomenon appears to be linked to the record warmth of the past decade, as well as with forest management choices. (Read More) Read more
The Southwest Monsoon Under Climate Change: What the Models Tell (and Don’t Tell) Us Oct. 15, 2010 Now that we (hopefully) have a better understanding of how climate models make long-term, generalized projections, can we use them to model our monsoon to figure out how it might be different under global climate change? The answer is yes and no, and that has to do with scale. To understand that, we first need to consider how the monsoon works. (Read More) Figure 1: The upper-level Bermuda High extending to the west in July, when our monsoon begins. The red colors are higher pressures; the center of the Bermuda High is marked by an 'H'. This image is from the National Weather Service. Read more