@misc{BlockDenfeldStockwelletal.2019,
  author    = {Block, Benjamin D. and Denfeld, Blaize A. and Stockwell, Jason D. and Flaim, Giovanna and Grossart, Hans-Peter and Knoll, Lesley B. and Maier, Dominique B. and North, Rebecca L. and Rautio, Milla and Rusak, James A. and Sadro, Steve and Weyhenmeyer, Gesa A. and Bramburger, Andrew J. and Branstrator, Donn K. and Salonen, Kalevi and Hampton, Stephanie E.},
  title     = {The unique methodological challenges of winter limnology},
  series = {Limnology and Oceanography: Methods},
  volume    = {17},
  journal   = {Limnology and Oceanography: Methods},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1541-5856},
  doi       = {10.1002/lom3.10295},
  pages     = {42 -- 57},
  year      = {2019},
  abstract  = {Winter is an important season for many limnological processes, which can range from biogeochemical transformations to ecological interactions. Interest in the structure and function of lake ecosystems under ice is on the rise. Although limnologists working at polar latitudes have a long history of winter work, the required knowledge to successfully sample under winter conditions is not widely available and relatively few limnologists receive formal training. In particular, the deployment and operation of equipment in below 0 degrees C temperatures pose considerable logistical and methodological challenges, as do the safety risks of sampling during the ice-covered period. Here, we consolidate information on winter lake sampling and describe effective methods to measure physical, chemical, and biological variables in and under ice. We describe variation in snow and ice conditions and discuss implications for sampling logistics and safety. We outline commonly encountered methodological challenges and make recommendations for best practices to maximize safety and efficiency when sampling through ice or deploying instruments in ice-covered lakes. Application of such practices over a broad range of ice-covered lakes will contribute to a better understanding of the factors that regulate lakes during winter and how winter conditions affect the subsequent ice-free period.},
  language  = {en}
}
@article{WeyhenmeyerMackayStockwelletal.2017,
  author    = {Weyhenmeyer, Gesa A. and Mackay, Murray and Stockwell, Jason D. and Thiery, Wim and Grossart, Hans-Peter and Augusto-Silva, Petala B. and Baulch, Helen M. and de Eyto, Elvira and Hejzlar, Josef and Kangur, Kuelli and Kirillin, Georgiy and Pierson, Don C. and Rusak, James A. and Sadro, Steven and Woolway, R. Iestyn},
  title     = {Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming},
  series = {Scientific reports},
  volume    = {7},
  journal   = {Scientific reports},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/srep43890},
  pages     = {9},
  year      = {2017},
  abstract  = {Citizen science projects have a long history in ecological studies. The research usefulness of such projects is dependent on applying simple and standardized methods. Here, we conducted a citizen science project that involved more than 3500 Swedish high school students to examine the temperature difference between surface water and the overlying air (T-w-T-a) as a proxy for sensible heat flux (Q(H)). If Q(H) is directed upward, corresponding to positive T-w-T-a, it can enhance CO2 and CH4 emissions from inland waters, thereby contributing to increased greenhouse gas concentrations in the atmosphere. The students found mostly negative T-w-T-a across small ponds, lakes, streams/rivers and the sea shore (i.e. downward Q(H)), with T-w-T-a becoming increasingly negative with increasing T-a. Further examination of T-w-T-a using high-frequency temperature data from inland waters across the globe confirmed that T-w-T-a is linearly related to T-a. Using the longest available high-frequency temperature time series from Lake Erken, Sweden, we found a rapid increase in the occasions of negative T-w-T-a with increasing annual mean T-a since 1989. From these results, we can expect that ongoing and projected global warming will result in increasingly negative T-w-T-a, thereby reducing CO2 and CH4 transfer velocities from inland waters into the atmosphere.},
  language  = {en}
}