uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Weyhenmeyer, Gesa A.ORCID iD iconorcid.org/0000-0002-4013-2281
Alternative names
Publications (10 of 163) Show all publications
Nydahl, A., Wallin, M. & Weyhenmeyer, G. A. (2020). Diverse drivers of long-term pCO2 increases across thirteen boreal lakes and streams. INLAND WATERS
Open this publication in new window or tab >>Diverse drivers of long-term pCO2 increases across thirteen boreal lakes and streams
2020 (English)In: INLAND WATERS, ISSN 2044-2041, E-ISSN 2044-205XArticle in journal (Refereed) Accepted
National Category
Biological Sciences
Research subject
Biology with specialization in Limnology
Identifiers
urn:nbn:se:uu:diva-390881 (URN)
Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2020-05-19
Nydahl, A., Wallin, M., Laudon, H. & Weyhenmeyer, G. A. (2020). Groundwater carbon within a boreal catchment – spatiotemporal variability of a hidden aquatic carbon pool. Journal of Geophysical Research - Biogeosciences, 125(1)
Open this publication in new window or tab >>Groundwater carbon within a boreal catchment – spatiotemporal variability of a hidden aquatic carbon pool
2020 (English)In: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, E-ISSN 2169-8961, Vol. 125, no 1Article in journal (Refereed) Published
National Category
Biological Sciences
Research subject
Biology with specialization in Limnology
Identifiers
urn:nbn:se:uu:diva-390878 (URN)10.1029/2019JG005244 (DOI)
Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2020-02-06Bibliographically approved
Nydahl, A., Wallin, M., Tranvik, L., Hiller, C., Attermeyer, K., Garrison, J. A., . . . Weyhenmeyer, G. A. (2019). Colored organic matter increases CO2 in meso-eutrophic lake water through altered light climate and acidity. Limnology and Oceanography, 64(2), 744-756
Open this publication in new window or tab >>Colored organic matter increases CO2 in meso-eutrophic lake water through altered light climate and acidity
Show others...
2019 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, no 2, p. 744-756Article in journal (Refereed) Published
Abstract [en]

Many surface waters across the boreal region are browning due to increased concentrations of colored allochthonous dissolved organic carbon (DOC). Browning may stimulate heterotrophic metabolism, may have a shading effect constraining primary production, and may acidify the water leading to decreased pH with a subsequent shift in the carbonate system. All these effects are expected to result in increased lake water carbon dioxide (CO2) concentrations. We tested here these expectations by assessing the effects of both altered allochthonous DOC input and light conditions through shading on lake water CO2 concentrations. We used two mesocosm experiments with water from the meso‐eutrophic Lake Erken, Sweden, to determine the relative importance of bacterial activities, primary production, and shifts in the carbonate system on CO2 concentrations. We found that DOC addition and shading resulted in a significant increase in partial pressure of CO2 (pCO2) in all mesocosms. Surprisingly, there was no relationship between bacterial activities and pCO2. Instead the experimental reduction of light by DOC and/or shading decreased the photosynthesis to respiration ratio leading to increased pCO2. Another driving force behind the observed pCO2 increase was a significant decrease in pH, caused by a decline in photosynthesis and the input of acidic DOC. Considering that colored allochthonous DOC may increase in a warmer and wetter climate, our results could also apply for whole lake ecosystems and pCO2 may increase in many lakes through a reduction in the rate of photosynthesis and decreased pH.

National Category
Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-366220 (URN)10.1002/lno.11072 (DOI)000461865500022 ()
Available from: 2018-11-18 Created: 2018-11-18 Last updated: 2020-03-09Bibliographically approved
Knoll, L. B., Sharma, S., Denfeld, B. A., Flaim, G., Hori, Y., Magnuson, J. I., . . . Weyhenmeyer, G. A. (2019). Consequences of lake and river ice loss on cultural ecosystem services. Limnology and Oceanography Letters, 4(5), 119-131
Open this publication in new window or tab >>Consequences of lake and river ice loss on cultural ecosystem services
Show others...
2019 (English)In: Limnology and Oceanography Letters, ISSN 2378-2242, Vol. 4, no 5, p. 119-131Article in journal (Refereed) Published
Abstract [en]

People extensively use lakes and rivers covered by seasonal ice. Although ice cover duration has been declining over the past 150 years for Northern Hemisphere freshwaters, we know relatively little about how ice loss directly affects humans. Here, we synthesize the cultural ecosystem services (i.e., services that provide intangible or nonmaterial benefits) and associated benefits supported by inland ice. We also provide, for the first time, empirical examples that give quantitative evidence for a winter warming effect on a wide range of ice-related cultural ecosystem services and benefits. We show that in recent decades, warmer air temperatures delayed the opening date of winter ice roads and led to cancellations of spiritual ceremonies, outdoor ice skating races, and ice fishing tournaments. Additionally, our synthesis effort suggests unexploited data sets that allow for the use of integrative approaches to evaluate the interplay between inland ice loss and society.

Place, publisher, year, edition, pages
WILEY, 2019
National Category
Oceanography, Hydrology and Water Resources Ecology
Identifiers
urn:nbn:se:uu:diva-397316 (URN)10.1002/lol2.10116 (DOI)000488243300002 ()
Funder
The Kempe Foundations
Available from: 2019-11-19 Created: 2019-11-19 Last updated: 2019-11-25Bibliographically approved
Engel, F., Drakare, S. & Weyhenmeyer, G. A. (2019). Environmental conditions for phytoplankton influenced carbon dynamics in boreal lakes. Aquatic Sciences, 81(2), Article ID 35.
Open this publication in new window or tab >>Environmental conditions for phytoplankton influenced carbon dynamics in boreal lakes
2019 (English)In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 81, no 2, article id 35Article in journal (Refereed) Published
Abstract [en]

The partial pressure of CO2 (pCO(2)) in lake water, and thus CO2 emissions from lakes are controlled by hydrologic inorganic carbon inputs into lakes, and in-lake carbon transformation (mainly organic carbon mineralization and CO2 uptake by primary producers). In boreal lakes, CO2 uptake by phytoplankton is often considered to be of minor importance. At present, however, it is not known in which and how many boreal lakes phytoplankton CO2 uptake has a sizeable influence on the lake water pCO(2). Using water physico-chemical and phytoplankton data from 126 widely spread Swedish lakes from 1992 to 2012, we found that pCO(2) was negatively related to phytoplankton carbon in lakes in which the phytoplankton share in TOC (C-phyto:TOC ratio) exceeded 5%. Total phosphorus concentration (TP) was the strongest predictor of spatial variation in the C-phyto:TOC ratio, where C-phyto:TOC ratios>5% occurred in lakes with TP>30 mu gl(-1). These lakes were located in the hemi-boreal zone of central and southern Sweden. We conclude that during summer, phytoplankton CO2 uptake can reduce the pCO(2) not only in warm eutrophic lakes, but also in relatively nutrient poor hemi-boreal lakes.

Place, publisher, year, edition, pages
SPRINGER BASEL AG, 2019
Keywords
Phytoplankton, CO2 emission, Authochthonous organic carbon, TOC, Global carbon cycle, Lake carbon cycling
National Category
Environmental Sciences Ecology
Identifiers
urn:nbn:se:uu:diva-380430 (URN)10.1007/s00027-019-0631-6 (DOI)000461138400001 ()
Funder
Swedish Research Council, 2016-04153EU, Horizon 2020, 643052Knut and Alice Wallenberg FoundationSwedish Environmental Protection AgencySwedish Agency for Marine and Water Management
Available from: 2019-03-29 Created: 2019-03-29 Last updated: 2019-03-29Bibliographically approved
Boy, M., Thomson, E. S., Acosta Navarro, J.-C., Arnalds, O., Batchvarova, E., Bäck, J., . . . Kulmala, M. (2019). Interactions between the atmosphere, cryosphere, and ecosystems at northern high latitudes. Atmospheric Chemistry And Physics, 19(3), 2015-2061
Open this publication in new window or tab >>Interactions between the atmosphere, cryosphere, and ecosystems at northern high latitudes
Show others...
2019 (English)In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 19, no 3, p. 2015-2061Article in journal (Refereed) Published
Abstract [en]

The Nordic Centre of Excellence CRAICC (Cryosphere-Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk in the years 2011-2016, is the largest joint Nordic research and innovation initiative to date, aiming to strengthen research and innovation regarding climate change issues in the Nordic region. CRAICC gathered more than 100 scientists from all Nordic countries in a virtual centre with the objectives of identifying and quantifying the major processes controlling Arctic warming and related feedback mechanisms, outlining strategies to mitigate Arctic warming, and developing Nordic Earth system modelling with a focus on short-lived climate forcers (SLCFs), including natural and anthropogenic aerosols. The outcome of CRAICC is reflected in more than 150 peer-reviewed scientific publications, most of which are in the CRAICC special issue of the journal Atmospheric Chemistry and Physics. This paper presents an overview of the main scientific topics investigated in the centre and provides the reader with a state-of-the-art comprehensive summary of what has been achieved in CRAICC with links to the particular publications for further detail. Faced with a vast amount of scientific discovery, we do not claim to completely summarize the results from CRAICC within this paper, but rather concentrate here on the main results which are related to feedback loops in climate change-cryosphere interactions that affect Arctic amplification.

Place, publisher, year, edition, pages
COPERNICUS GESELLSCHAFT MBH, 2019
National Category
Meteorology and Atmospheric Sciences Climate Research
Identifiers
urn:nbn:se:uu:diva-378374 (URN)10.5194/acp-19-2015-2019 (DOI)000458626000003 ()
Funder
EU, Horizon 2020, 641816NordForsk, 26060
Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-03-07Bibliographically approved
Arndt, D. S., Weyhenmeyer, G. A. & Bettio, L. (2019). INTRODUCTION: Lake surface temperature in State of the Climate in 2018. Bulletin of The American Meteorological Society - (BAMS), 100(9), S1-+
Open this publication in new window or tab >>INTRODUCTION: Lake surface temperature in State of the Climate in 2018
2019 (English)In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 100, no 9, p. S1-+Article in journal (Refereed) Published
National Category
Climate Research
Identifiers
urn:nbn:se:uu:diva-396672 (URN)000489716700003 ()
Note

For complete list of authors see http://dx.doi.org/None

Available from: 2019-11-07 Created: 2019-11-07 Last updated: 2020-02-18Bibliographically approved
Niklasdotter Scherrer, K. J., Kortsch, S., Varpe, Ø., Weyhenmeyer, G. A., Gulliksen, B. & Primicerio, R. (2019). Mechanistic model identifies increasing light availability due to sea ice reductions as cause for increasing macroalgae cover in the Arctic. Limnology and Oceanography, 64(1), 330-341
Open this publication in new window or tab >>Mechanistic model identifies increasing light availability due to sea ice reductions as cause for increasing macroalgae cover in the Arctic
Show others...
2019 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, no 1, p. 330-341Article in journal (Refereed) Published
Abstract [en]

In the Arctic, rising seawater temperatures and increasing underwater light caused by reductions in sea ice cover are expected to change the structure of arctic marine communities. Substantial, sometimes sudden, increases in macroalgal productivity and biomass have already been observed in arctic rocky bottom communities. These macroalgal responses have been attributed to increasing temperature and light, but the relative importance of the suggested drivers of change has not yet been assessed. In this study, we used a mechanistic competition model to unravel the effects of temperature and light on benthic community structure and algae dominance, focusing on key algae species: red calcareous algae and macroalgal fronds. We find that light is the primary driver of increases in macroalgal coverage, whereas increased seawater temperature plays a secondary role. Shifts leading to macroalgae dominated communities may be mediated by competitive interactions, and are likely due to three light-related processes: earlier sea ice break-out at high latitudes can result in an exponential increase in the cumulative amount of light that enters the water column during a year; threshold effect in light requirements for algal growth; and light requirements of calcareous algae being substantially lower than those of macroalgae. With continued warming, our modeling results suggest that reduced sea ice coverage and increased light availability will favor dominance of macroalgae, which due to their key ecological role are expected to alter the structure and functioning of arctic rocky bottom ecosystems.

National Category
Oceanography, Hydrology and Water Resources Ecology
Identifiers
urn:nbn:se:uu:diva-377377 (URN)10.1002/lno.11043 (DOI)000456720900023 ()
Available from: 2019-02-25 Created: 2019-02-25 Last updated: 2019-02-25Bibliographically approved
Engel, F., Attermeyer, K., Ayala, A. I., Fischer, H., Kirchesch, V., Pierson, D. & Weyhenmeyer, G. A. (2019). Phytoplankton gross primary production increases along cascading impoundments in a temperate, low-discharge river: Insights from high frequency water quality monitoring. Scientific Reports, 9, Article ID 6701.
Open this publication in new window or tab >>Phytoplankton gross primary production increases along cascading impoundments in a temperate, low-discharge river: Insights from high frequency water quality monitoring
Show others...
2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 6701Article in journal (Refereed) Published
Abstract [en]

Damming alters carbon processing along river continua. Estimating carbon transport along rivers intersected by multiple dams requires an understanding of the effects of cascading impoundments on the riverine metabolism. We analyzed patterns of riverine metabolism and phytoplankton biomass (chlorophyll a; Chla) along a 74.4-km river reach intersected by six low-head navigation dams. Calculating gross primary production (GPP) from continuous measurements of dissolved oxygen concentration, we found a maximum increase in the mean GPP by a factor of 3.5 (absolute difference of 0.45 g C m−3 d−1) along the first 26.5 km of the study reach, while Chla increased over the entire reach by a factor of 2.9 (8.7 µg l−1). In the intermittently stratified section of the deepest impoundment the mean GPP between the 1 and 4 m water layer differed by a factor of 1.4 (0.31 g C m−3 d−1). Due to the strong increase in GPP, the river featured a wide range of conditions characteristic of low- to medium-production rivers. We suggest that cascading impoundments have the potential to stimulate riverine GPP, and conclude that phytoplankton CO2 uptake is an important carbon flux in the river Saar, where a considerable amount of organic matter is of autochthonous origin.

National Category
Environmental Sciences
Identifiers
urn:nbn:se:uu:diva-382755 (URN)10.1038/s41598-019-43008-w (DOI)000466351100060 ()31040329 (PubMedID)
Funder
Swedish Research Council, 2016-04153EU, Horizon 2020, 643052Knut and Alice Wallenberg Foundation
Available from: 2019-05-02 Created: 2019-05-02 Last updated: 2019-05-20Bibliographically approved
Woolway, R. I., Weyhenmeyer, G. A., Schmid, M., Dokulil, M. T., de Eyto, E., Maberly, S. C., . . . Merchant, C. J. (2019). Substantial increase in minimum lake surface temperatures under climate change. Climatic Change, 155(1), 81-94
Open this publication in new window or tab >>Substantial increase in minimum lake surface temperatures under climate change
Show others...
2019 (English)In: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 155, no 1, p. 81-94Article in journal (Refereed) Published
Abstract [en]

The annual minimum of lake surface water temperature influences ecological and biogeochemical processes, but variability and change in this extreme have not been investigated. Here, we analysed observational data from eight European lakes and investigated the changes in annual minimum surface water temperature. We found that between 1973 and 2014, the annual minimum lake surface temperature has increased at an average rate of + 0.35 degrees Cdecade(-1), comparable to the rate of summer average lake surface temperature change during the same period (+ 0.32 degrees C decade(-1)). Coherent responses to climatic warming are observed between the increase in annual minimum lake surface temperature and the increase in winter air temperature variations. As a result of the rapid warming of annual minimum lake surface temperatures, some of the studied lakes no longer reach important minimum surface temperature thresholds that occur in winter, with complex and significant potential implications for lakes and the ecosystem services that they provide.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Warming, Water, trends, Extremes, Winter limnology
National Category
Climate Research
Identifiers
urn:nbn:se:uu:diva-390916 (URN)10.1007/s10584-019-02465-y (DOI)000473162200005 ()
Funder
EU, Horizon 2020, 640171
Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2019-08-15Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4013-2281

Search in DiVA

Show all publications