Beryllium‐7 wet deposition variation with storm height, synoptic classification, and tree canopy state in the mid‐Atlantic USA

Short‐lived fallout isotopes, such as beryllium‐7 (7Be), are increasingly used as erosion and sediment tracers in watersheds. 7Be is produced in the atmosphere and delivered to the Earth's surface primarily in precipitation. However, relatively little has been published about the variation in 7Be wet deposition caused by storm type and vegetation cover. Our analysis of precipitation, throughfall, and sediments in two forested, headwater catchments in the mid‐Atlantic USA indicates significant variation in isotope deposition with storm type and storm height. Individual summer convective thunderstorms were associated with 7Be activity concentrations up to 5.0 Bq l−1 in precipitation and 4.7 Bq l−1 in throughfall, while single‐event wet depositional fluxes reached 168 Bq m−2 in precipitation and 103 Bq m−2 in throughfall. Storms originating from the continental USA were associated with lower 7Be activity concentrations and single‐event wet depositional fluxes for precipitation (0.7–1.2 Bq l−1 and 15.8–65.0 Bq m−2) and throughfall (0.1–0.3 Bq l−1 and 13.5–98.9 Bq m−2). Tropical systems had relatively low activity concentrations, 0.2–0.5 Bq l−1 in precipitation and 0.2–1.0 Bq l−1 in throughfall, but relatively high single‐event depositional fluxes due to large rainfall volumes, 32.8–67.6 Bq m−2 in precipitation and 25.7–134 Bq m−2 in throughfall. The largest sources of 7Be depositional variation were attributed to storm characteristics including precipitation amount and maximum storm height. 7Be activity associated with fluvial suspended sediments also exhibited the highest concentration and variability in summer (175–1450 Bq kg−1). We conclude the dominant source of variation on event‐level 7Be deposition is storm type. Our results illustrate the complex relationships between 7Be deposition in precipitation and throughfall and demonstrate event‐scale relationships between the 7Be in precipitation and on suspended sediment. Copyright © 2015 John Wiley & Sons, Ltd.

[1]  C. Renshaw,et al.  Seasonal controls on meteoric 7Be in coarse‐grained river channels , 2014 .

[2]  L. Mabit,et al.  Assumptions and challenges in the use of fallout beryllium-7 as a soil and sediment tracer in river basins , 2013 .

[3]  P. Swarzenski,et al.  Short-term variability of 7Be atmospheric deposition and watershed response in a Pacific coastal stream, Monterey Bay, California, USA. , 2013, Journal of environmental radioactivity.

[4]  D. Walling.  Beryllium‐7: The Cinderella of fallout radionuclide sediment tracers? , 2013 .

[5]  T. Gomi,et al.  Interception of the Fukushima reactor accident‐derived137Cs, 134Cs and 131I by coniferous forest canopies , 2012 .

[6]  L. Couldrick,et al.  Sorption behaviour of beryllium-7 and implications for its use as a sediment tracer , 2012 .

[7]  J. V. Van Stan,et al.  The effects of phenoseason and storm characteristics on throughfall solute washoff and leaching dynamics from a temperate deciduous forest canopy. , 2012, The Science of the total environment.

[8]  N. Nicholls,et al.  Relating global precipitation to atmospheric fronts , 2012 .

[9]  M. Baskaran,et al.  Meteoric 7Be and 10Be as Process Tracers in the Environment , 2012 .

[10]  C. Sanders,et al.  Lead-210 and Beryllium-7 fallout rates on the southeastern coast of Brazil. , 2011, Journal of environmental radioactivity.

[11]  M. A. Rana,et al.  Wet depositional fluxes of 210Pb- and 7Be-bearing aerosols at two different altitude cities of North Pakistan , 2011 .

[12]  M. Baskaran,et al.  Depositional fluxes and concentrations of 7Be and 210Pb in bulk precipitation and aerosols at the interface of Atlantic and Mediterranean coasts in Spain , 2011 .

[13]  E. Echer,et al.  Cosmogenic isotope 7Be: A case study of depositional processes in Rio de Janeiro in 2008–2009 , 2011 .

[14]  G. Paschmann,et al.  Triggering of magnetic reconnection in a magnetosheath current sheet due to compression against the magnetopause , 2011 .

[15]  Bruce K. Wylie,et al.  Upscaling carbon fluxes over the Great Plains grasslands: Sinks and sources , 2011 .

[16]  A. Elmore,et al.  Beryllium‐7 in soils and vegetation along an arid precipitation gradient in Owens Valley, California , 2011 .

[17]  F. Magilligan,et al.  Constraining the timescales of sediment sequestration associated with large woody debris using cosmogenic 7Be , 2010 .

[18]  H. Velasco,et al.  Short-term seasonal variability in 7Be wet deposition in a semiarid ecosystem of central Argentina. , 2009, Journal of environmental radioactivity.

[19]  P. Froidevaux,et al.  Determination of radionuclide levels in rainwater using ion exchange resin and gamma-spectrometry. , 2009, Journal of environmental radioactivity.

[20]  Chad W. Higgins,et al.  Albedo effect on radiative errors in air temperature measurements , 2009 .

[21]  G. Schmidt,et al.  Short‐term production and synoptic influences on atmospheric 7Be concentrations , 2009 .

[22]  D. Hölscher,et al.  Rainfall partitioning along a tree diversity gradient in a deciduous old‐growth forest in Central Germany , 2009 .

[23]  D. Walling,et al.  Extending the timescale for using beryllium 7 measurements to document soil redistribution by erosion , 2009 .

[24]  Gordon R. Gilmore,et al.  Practical Gamma-ray Spectrometry, 2nd Edition , 2008 .

[25]  Y. Kuwahara,et al.  Measurements of short-lived cosmogenic nuclides in rain samples , 2006 .

[26]  D. Walling,et al.  Use of beryllium-7 to document soil redistribution following forest harvest operations. , 2006, Journal of environmental quality.

[27]  A. Ioannidou,et al.  Precipitation scavenging of 7Be and 137Cs radionuclides in air. , 2006, Journal of environmental radioactivity.

[28]  J. Cartwright,et al.  Cosmogenic 7Be deposition in North Wales: 7Be concentrations in sheep faeces in relation to altitude and precipitation. , 2005, Journal of environmental radioactivity.

[29]  J. Dibb,et al.  Stratospheric influence on the northern North American free troposphere during TOPSE: 7Be as a stratospheric tracer , 2003 .

[30]  D. Walling,et al.  Using cosmogenic beryllium–7 as a tracer in sediment budget investigations , 2002 .

[31]  S. Norton,et al.  Environmental Chemistry of Beryllium-7 , 2002 .

[32]  J. Dominik,et al.  Factors controlling 7Be and 210Pb atmospheric deposition as revealed by sampling individual rain events in the region of Geneva, Switzerland. , 2001, Journal of environmental radioactivity.

[33]  Guebuem Kim,et al.  Factors Influencing the Atmospheric Depositional Fluxes of Stable Pb, 210Pb, and 7Be into Chesapeake Bay , 2000 .

[34]  Hengchun Ye,et al.  Relationships between Synoptic Climatology and Atmospheric Pollution at 4 US Cities , 1999 .

[35]  Klaus P. Hoinka,et al.  Statistics of the Global Tropopause Pressure , 1998 .

[36]  Brent Yarnal,et al.  USING SYNOPTIC CLIMATOLOGY TO DEFINE REPRESENTATIVE DISCHARGE EVENTS , 1997 .

[37]  W. Casey,et al.  Atmospheric fluxes and marsh-soil inventories of /sup 7/Be and /sup 210/Pb , 1996 .

[38]  Gordon R. Gilmore,et al.  Practical Gamma‐ray Spectrometry , 1995 .

[39]  M. Baskaran.  A search for the seasonal variability on the depositional fluxes of 7Be and 210Pb , 1995 .

[40]  P. Samson,et al.  Aggregation of Selected Three-Day Periods to Estimate Annual and Seasonal Wet Deposition Totals for Sulfate, Nitrate, and Acidity. Part I: A Synoptic and Chemical Climatology for Eastern North America , 1995 .

[41]  Y. Ishikawa,et al.  Precipitation scavenging studies of radionuclides in air using cosmogenic 7Be , 1995 .

[42]  Robert Dolan,et al.  Synoptic climatology of atlantic coast North-Easters , 1993 .

[43]  E. Canuel,et al.  Seasonal variations in 7Be activity in the sediments of Cape Lookout Bight, North Carolina , 1990 .

[44]  C. You,et al.  The partition of Be between soil and water , 1989 .

[45]  W. Casey,et al.  Atmospheric fluxes and marsh‐soil inventories of 7Be and 210Pb , 1985 .

[46]  P. K. Malhotra,et al.  On the production of radioisotopes in the atmosphere by cosmic radiation and their application to meteorology , 1958 .