23 November 2016

A conversation with Zack Labe

Posted by Callan

zlabe_photoYesterday, I mentioned climate change visualizer extraordinaire Zack Labe. As delineated then, he’s a PhD student at U.C. – Irvine in the Earth Systems Science department. He’s producing some really excellent #dataviz on climate change.

Today, I’d like to share a short exchange I had with Zack about his work.

1)      Please give Mountain Beltway readers a sense of your background, leading up to what you’re working on now for your PhD.

My interest in the weather stems back as far as I can remember. I studied atmospheric sciences at Cornell University and have always had an interest in understanding broader connections in the large-scale atmosphere for weather prediction. While the Arctic may seem remote to many living in the tropics and mid-latitudes, there are important atmospheric teleconnections between these two regions that can affect our weather and climate. Changes in the Arctic, such as warming surface temperatures and decreasing sea ice, are happening a lot more quickly than other parts of the globe (“Arctic Amplification”). However, our understanding of these relationships remains very uncertain, especially in the presence of climate change.

My PhD work at the University of California, Irvine is using a combination of observations, reanalysis data, and sensitivity modeling experiments to try to better understand the critical relationships between the Arctic and mid-latitudes with a focus on how changes in sea ice and snow cover may respond or drive the large-scale atmospheric circulation.

2)      At what point did you get involved in the preparation of elegant figures relating to climate data? When did you get involved in social media / outreach?

Climate change science communication is not working. While broader public acceptance continues to grow, there remain significant challenges in how to tell this story. I’ve found that a big barrier exists in our science figures. Many times these plots are full of jargon, unclear labels, and/or poor choices of color schemes. I’ve used social media (Twitter) as an outlet for sharing science data and observations that (I hope) bridges the gap between science and non-science backgrounds.

My goals are to both visualize and explain where science data derives, and how do scientists evaluate, criticize, and analyze this information. Science is not meant to be kept hidden away in the halls of academia, but to share and better understand the world around us. Some of the most questions I get revolve around how can people find science data and read more information about it. I’ve found that climate visualizations provide an avenue that helps allow people to become involved with science and critically assess this information.

3)      How is the data you present in your figures gathered?

All of the sea ice and Arctic climate data is publicly available through sources such as NASA, JAXA, and other meteorological/climate centers. I try to provide a data source link in each of the figures and sometimes an associated Python code script for those interested in replicating their own plots. There is immense amount of freely available climate data, but the challenge is often where to find this information. I am encouraged that science will continue to advance and expand the amount of open access data and code available to the public.

4)      Is what’s happening now in the Arctic anomalous? What about the Antarctic? What’s going on?

The persistent atmospheric circulation from a deep low pressure anomaly over the North Pacific and a record ridge over Eurasia allowed warmer air to advect into the Arctic on both the Pacific and Atlantic sides. Warmer sea surface temperatures and more open ocean waters have also contributed to the slow expansion of sea ice this fall, particularly in the Barents and Kara Seas. As a result of this anomalous atmospheric pattern and the continued warming of the Arctic from climate change, temperatures were able to rise well above normal in addition to record low sea ice extent.

5)      Can you address the suggestion made a few days back that “a broken sensor” was a possible explanation?

During the spring of 2016, the instrument on the DMSP-F17 satellite used for sea ice concentration data by the NSIDC began recording erroneous data. The NSIDC made the transition to the DMSP-F18 satellite passive microwave instrument and provided a consistent and continuous record of sea ice concentration. More information/validation between satellites can be found from the NSIDC at http://nsidc.org/the-drift/data-update/sea-ice-index-processing-resumed-with-dmsp-f18-satellite-data/.

Therefore, the current data from both the Northern and Southern Hemisphere is not affected by any sensor issues. Additionally, there are other tools for sea ice data, including the AMSR2 instrument available from JAXA, which confirm the anomalously low sea ice in the Arctic and Antarctic.

6)      Do you have any predictions for what we can expect to see in the weeks to come?

Sea ice is susceptible to large variability as a result of atmospheric and oceanic interactions. However, as we are already seeing, the high temperatures anomalies are beginning to wane over the Arctic basin. As air temperatures and sea surface temperatures continue to cool, it is likely sea ice extent will continue to expand across the marginal seas.

The persistence of these abnormally high air and ocean temperatures have significantly reduced sea ice thickness across much of the Arctic, and this may play a role going forward into the 2017 melt season. Overall despite large interannual variability, we are continuing to see a long-term reduction in sea ice thickness and the fraction of multi-year ice.

I would echo this point – regardless of whether the anomaly we’ve observed over the past few months turns out to be a one-time incident, there is clear evidence that the long-term trend is toward less sea ice, less sea volume, younger sea ice, and less glacial ice. That trend will stand independent of whether this is a unique incident. We should be concerned at the changes we are observing in this aspect of the cryosphere.

I’m grateful to Zack for taking the time to share his insights here. Do you have any other questions you’d like to pose to Zack? If so, drop them into the comments thread.