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Ron Lindsay

Senior Principal Physicist

Email

lindsay@apl.washington.edu

Phone

206-543-5409

Biosketch

Ron Lindsay is interested in how the sea ice in the Arctic moves, grows, and decays in response to changing environmental conditions and how the changes in the ice pack are impacting the atmosphere above. To pursue these research themes he uses a wide variety of in situ and remote sensing data and numerical models. In situ data is from ice camps, buoys, submarines, and moorings, while remote sensing data is from many different sensors. He is particularly interested in collecting, comparing, and utilizing ice thickness measurements and has compiled a public data set of measurements from submarines, moorings, aircraft, and satellites. In support of these interests he has joined the IceBridge science team to help direct a NASA program to monitor ice thickness from aircraft. He has conducted extensive analyses of the output of the retrospective Polar Science Center sea ice model to determine how, where, and why the ice pack is rapidly changing. The model is also the basis for a statistical predictive scheme he has developed for forecasting the ice extent months in advance, either for the Arctic as a whole or for specific regions. Finally, he is developing a capability for modeling the response of the atmosphere to changing pack ice conditions in order to understand the extent to which the heat absorbed in the open water areas in the summer slows the growth of ice in the winter. Ron has been conducting Arctic research for over 35 years and has been with the Polar Science Center since 1988.

Department Affiliation

Polar Science Center

Education

B.S. Physics, University of California at Davis, 1968

M.S. Atmospheric Sciences, University of Washington, 1976

Projects

RADARSAT Geophysical Processor System at the Polar Science Center

 

Bering Strait: Pacific Gateway to the Arctic

The Bering Strait is the only Pacific gateway to the Arctic. Since 1990, under various funding, APL-UW has been measuring properties of the Pacific inflow using long-term in situ moorings, supported by annual cruises. Data, papers, cruise reports, plans, and results are available.

 

The Fate of Summertime Arctic Ocean Heating: A Study of Ice-Albedo Feedback on Seasonal to Interannual Time Scales

The main objective of this study is to determine the fate of solar energy absorbed by the arctic seas during summer, with a specific focus on its impact on the sea ice pack. Investigators further seek to understand the fate of this heat during the winter and even beyond to the following summer. Their approach is use a coupled sea ice–ocean model forced by atmospheric reanalysis fields, with and without assimilation of satellite-derived ice and ocean variables. They are also using satellite-derived ocean color data to help determine light absorption in the upper ocean.

 

More Projects

Publications

2000-present and while at APL-UW

Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations

Lindsay, R., and A. Schweiger, "Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations," Cryosphere, 9, 269-283, doi:10.5194/tc-9-269-2015, 2015.

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10 Feb 2015

Sea ice thickness is a fundamental climate state variable that provides an integrated measure of changes in the high-latitude energy balance. However, observations of mean ice thickness have been sparse in time and space, making the construction of observation-based time series difficult. Moreover, different groups use a variety of methods and processing procedures to measure ice thickness, and each observational source likely has different and poorly characterized measurement and sampling errors. Observational sources used in this study include upward-looking sonars mounted on submarines or moorings, electromagnetic sensors on helicopters or aircraft, and lidar or radar altimeters on airplanes or satellites. Here we use a curve-fitting approach to determine the large-scale spatial and temporal variability of the ice thickness as well as the mean differences between the observation systems, using over 3000 estimates of the ice thickness. The thickness estimates are measured over spatial scales of approximately 50 km or time scales of 1 month, and the primary time period analyzed is 2000–2012 when the modern mix of observations is available. Good agreement is found between five of the systems, within 0.15 m, while systematic differences of up to 0.5 m are found for three others compared to the five. The trend in annual mean ice thickness over the Arctic Basin is –0.58 ± 0.07 m decade-1 over the period 2000–2012. Applying our method to the period 1975–2012 for the central Arctic Basin where we have sufficient data (the SCICEX box), we find that the annual mean ice thickness has decreased from 3.59 m in 1975 to 1.25 m in 2012, a 65% reduction. This is nearly double the 36% decline reported by an earlier study. These results provide additional direct observational evidence of substantial sea ice losses found in model analyses.

Seasonal ice loss in the Beaufort Sea: Toward synchrony and prediction

Steele, M., S. Dickinson, J. Zhang, and R. Lindsay, "Seasonal ice loss in the Beaufort Sea: Toward synchrony and prediction," J. Geophys. Res., 120, 1118-1132, doi:10.1002/2014JC010247, 2015.

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1 Feb 2015

The seasonal evolution of sea ice loss in the Beaufort Sea during 1979–2012 is examined, focusing on differences between eastern and western sectors. Two stages in ice loss are identified: the Day of Opening (DOO) is defined as the spring decrease in ice concentration from its winter maximum below a value of 0.8 areal concentration; the Day of Retreat (DOR) is the summer decrease below 0.15 concentration. We consider three aspects of the subject, i.e., (i) the long-term mean, (ii) long-term linear trends, and (iii) interannual variability. We find that in the mean, DOO occurs earliest in the eastern Beaufort Sea (EBS) owing to easterly winds which act to thin the ice there, relative to the western Beaufort Sea (WBS) where ice has been generally thicker. There is no significant long-term trend in EBS DOO, although WBS DOO is in fact trending toward earlier dates. This means that spatial differences in DOO across the Beaufort Sea have been shrinking over the past 33 years, i.e., these dates are becoming more synchronous, a situation which may impact human and marine mammal activity in the area. Retreat dates are also becoming more synchronous, although with no statistical significance over the studied time period. Finally, we find that in any given year, an increase in monthly mean easterly winds of ~1 m/s during spring is associated with earlier summer DOR of 6–15 days, offering predictive capability with 2–4 months lead time.

Observations and modeling of atmospheric profiles in the arctic seasonal ice zone

Liu, Z., A. Schweiger, and R. Lindsay, "Observations and modeling of atmospheric profiles in the arctic seasonal ice zone," Mon. Wea. Rev., 143, 39-53, doi:, 2015.

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1 Jan 2015

The authors use the Polar Weather Research and Forecasting (WRF) Model to simulate atmospheric conditions during the Seasonal Ice Zone Reconnaissance Survey (SIZRS) in the summer of 2013 over the Beaufort Sea. With the SIZRS dropsonde data, the performance of WRF simulations and two forcing datasets is evaluated: the Interim ECMWF Re-Analysis (ERA-Interim) and the Global Forecast System (GFS) analysis. General features of observed mean profiles, such as low-level temperature inversion, low-level jet (LLJ), and specific humidity inversion are reproduced by all three models. A near-surface warm bias and a low-level moist bias are found in ERA-Interim. WRF significantly improves the mean LLJ, with a lower and stronger jet and a larger turning angle than the forcing. The improvement in the mean LLJ is likely related to the lower values of the boundary layer diffusion in WRF than in ERA-Interim and GFS, which also explains the lower near-surface temperature in WRF than the forcing. The relative humidity profiles have large differences between the observations, the ERA-Interim, and the GFS. The WRF simulated relative humidity closely resembles the forcings, suggesting the need to obtain more and better-calibrated humidity data in this region. The authors find that the sea ice concentrations in the ECMWF model are sometimes significantly underestimated due to an inappropriate thresholding mechanism. This thresholding affects both ERA-Interim and the ECMWF operational model. The scale of impact of this issue on the atmospheric boundary layer in the marginal ice zone is still unknown.

More Publications

In The News

Arctic sea ice "thinning dramatically," study finds

CBS News, Laura Geggel

Arctic sea ice -- the ice that freezes and floats on Arctic waters -- is thinning at a steadier and faster rate than researchers previously thought, a new study finds.

5 Mar 2015

Arctic sea ice is getting thinner faster than expected

The Guardian, Andrea Thompson

While the steady disappearance of sea ice in the Arctic has been one of the hallmark effects of global warming, research shows it is not only covering less of the planet, but it%u2019s also getting significantly thinner.

5 Mar 2015

Arctic sea ice is getting thinner, faster

MSN

While the steady disappearance of sea ice in the Arctic has been one of the hallmark effects of global warming, research shows it is not only covering less of the planet, but it's also getting significantly thinner.

5 Mar 2015

More News Items

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