Window on physics, the world of Moetasim Ashfaq

Dec 15, 2015
Moet Ashfaq

Dr. Moetasim Ashfaq (Moet), an atmospheric physicist in the Computing and Computational Sciences Directorate and Climate Change Science Institute (CCSI) at Oak Ridge National Laboratory (ORNL), spent his childhood and initial college years in Kashmir, Pakistan, home to some of the highest mountains in the world. It is perhaps not unexpected that Moet would one day work in climate science, coming from Pakistan, a country regarded by many as extremely vulnerable to climate change; however, he got here from there by a circuitous route.

Influenced by his older brother, Moet was set to finish college as a civil engineering major. Luckily for the climate science/climate modeling world he found this wasn’t for him and switched to physics, the first of several career-making changes. After obtaining an undergraduate degree in mathematics and physics, he moved to Islamabad to pursue graduate degrees in physics and computational physics. However, the problems he was dealing with, he says, were vastly different from those he deals with today: condensed matter physics, analogous to materials science.

The importance of mentors

While preparing to pursue a PhD in the United States, he was offered a job in Islamabad at the Global Change Impact Studies Centre (GCISC), the research arm of the Pakistan Ministry of Climate Change. At that time, Moet says, people in Pakistan didn’t typically get degrees in climate science, so the centre was pursuing people with physics backgrounds—lucky for him as he was a complete climate neophyte. He jokes that when asked during his interview what he thought was the cause of global warming, he speculated that it might be due to a hole in the ozone. He accepted an appointment with the centre based on the advice of his master’s advisor, who suggested that a break from his academic pursuits might be helpful and that if he liked the climate change arena, he might want to change the direction of his PhD.

He still had a few more corners to turn, but he had found his niche.

In condensed matter physics he felt that he was working on problems that didn’t seem to have much relevance to the real world, whereas with climate science, anything he learned, anything he read, he says “had direct applications . . . was more relatable to daily life.” That was the main attraction for him.

After 2 years at GCISC, Moet made a brief stop at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy, another move that was to play a role in his career. (Ironically, ICTP was founded by and named for a Pakistani Nobel Laureate in physics, Abdus Salam.) ICTP is a place where scientists from developing nations have the opportunity to meet and share ideas with scientists from around the world. It was his mentor at ICTP who suggested that Moet continue his education at Purdue, and a colleague of his, Noah Diffenbaugh (currently at Stanford), contacted Moet and offered him a graduate research assistantship at Purdue. Moet says that Noah and his mentorship strongly influenced his current career and choices in climate science research.

After obtaining his PhD in atmospheric sciences from Purdue, Moet joined ORNL as a postdoc in 2010 (he has the distinction of being the first postdoc at CCSI) and accepted a professional appointment in 2011.

Interesting science questions

When asked about his work, Moet says it can be described briefly as “the study of climate variability and change resulting from natural or anthropogenic causes, past, present, and future, and how it impacts natural and human systems”—particularly at fine (regional and subregional) scales. In pursuing this goal, he uses very high resolution climate models, some of which, he says, he has been using since he started in the field. So basically he is addressing climate change through modeling.

Two areas he specifically focuses on are the continental United States and south Asia, where he is from and where his research is showing an impact.

K2 in the Karakoram region of Pakistan.Due to the unique seasonality of this mountain range, the Karakoram can expect more snow over the next century in contrast to neighboring mountain ranges.

Recently, Moet was part of the groundbreaking team that solved the puzzle of the Karakoram glaciers. The Karakoram range, which spans the borders of China, India, and Pakistan, has the largest concentration of peaks over 8,000 m (26,247 ft) in height in the world, including the second highest peak in the world, K2 [8,611 m (28,251 ft)]. Globally, glaciers have been retreating due to warmer temperatures—except for one area, the Karakoram, where they not only aren’t retreating, but are actually growing—something referred to as the Karakoram anomaly. Through high resolution modeling Moet and his colleagues found this to be the result of the unique seasonality of precipitation in the region. Most of the precipitation in the Karakoram is received in the winter, when temperatures, while higher than in the past, are still below zero, and thus the precipitation feeds the glaciers (glaciers in other parts of the Himalayas receive most of their precipitation in the summer as rain). The research also indicated that this trend would continue through the 21st century. This discovery is of inestimable importance as more than a billion people are dependent on meltwater from glaciers in the Himalayas as a freshwater resource.

In the United States, his focus has been on future climate change up to about the middle of the 21st century. As part of this work, Moet and his colleagues have developed one of the highest resolution climate models covering the United States, using ORNL’s computing power, and they are using it to address what he refers to as “interesting science questions.”

  • What will be the effects of climate change on hydroelectric plants in the United States, and what will be the response?
  • How will projected higher temperatures in the future affect precipitation and, in turn, water stress?
  • How will tourism be affected in resort areas due to future variations in precipitation?
  • What are some of the collateral effects of extreme precipitation events (e.g., runoff) and their impacts?
  • How will extreme weather events affect critical infrastructure such as bridges?

Grand challenges

Moet’s previous research pointed out the possibility of a weaker summer monsoon over south Asia in response to increased greenhouse gas forcing, highlighting the uncertainty in future climate projections for this region. Moet says that the south Asian monsoon, on which 1.6 billion people are dependent, is a major challenge for climate modelers because “the models we use are not very skillful” at representing what is happening, primarily because the area is so complex. “Topographically it is the most complex region in the world, with 100 of the world’s tallest mountains in the region.” Ultimately, he says, they would like to build a modeling framework that can provide more reliable predictions for the region.

Another challenge, he says, is determining how large-scale changes will be felt at a fine scale, that is, at the local level, something he calls the “decision-making level.” “What I have learned over the last 10 or 12 years is that we are not ‘there’ yet. We can give a broad-scale picture, but the real challenge is to predict climate change at the scales that really matter.”

He believes another challenge for scientists is to find a balance between objectivity and sensationalism. An example is in the climate change arena, where he says things sometimes get sensationalized or exaggerated. This, he says, just tends to fuel climate change doubters.


Still a physicist at heart, Moet says that he is most influenced or inspired by scientists in the physics area, chief among them Nicola Tesla because he always thought outside the box. “He was unique . . . he had unique capabilities and unique ideas. And I think that is what we need in climate science to address the challenges we are facing.”

Inspiration in his daily work still comes from physics, which he refers to as his “passion.” “That is the way it should be . . . if you are interested in climate change, you want to understand the physical challenges.”

Freedom is also important to the scientific life, he says. Sometimes it can feel as though funding imperatives are impinging on scientific freedom, but overall there is a lot of freedom at ORNL, he says, even with the funding constraints.

The resources at the lab may not be what one typically thinks of as inspirational, but Moet says “they are magical,” allowing scientists to do things here that wouldn’t be possible anywhere else.

And the lab is a big supporter of the “think outside the box” ethos—which, as we already know, Moet is also a big fan of.

Moet’s work has been published in high impact journals ranging from the Bulletin of the American Meteorological Society to Nature Geoscience, Nature Climate Change, and Geophysical Research Letters. For more about Moet’s research and recent publications, please visit the CCSI website.

By VJ Ewing.  Posted 15 Dec, 2015  1:30 p.m.