Dynamical Downscaling over the Great Lakes Basin of North America Using the WRF Regional Climate Model: The Impact of the Great Lakes System on Regional Greenhouse Warming

2012 ◽  
Vol 25 (21) ◽  
pp. 7723-7742 ◽  
Author(s):  
Jonathan Gula ◽  
W. Richard Peltier
Keyword(s):  
Climate Change ◽  
North America ◽  
Great Lakes ◽  
Water Temperature ◽  
Lake Water ◽  
Regional Climate ◽  
Regional Model ◽  
Great Lakes Basin ◽  
Lake Model ◽  
The Impact

The Weather Research and Forecasting model (WRF) is employed to dynamically downscale global warming projections produced using the Community Climate System Model (CCSM). The analyses are focused on the Great Lakes Basin of North America and the climate change projections extend from the instrumental period (1979–2001) to midcentury (2050–60) at a spatial resolution of 10 km. Because WRF does not currently include a sufficiently realistic lake component, simulations are performed using lake water temperature provided by D.V. Mironov’s freshwater lake model “FLake” forced by atmospheric fields from the global simulations. Results for the instrumental era are first compared with observations to evaluate the ability of the lake model to provide accurate lake water temperature and ice cover and to analyze the skill of the regional model. It is demonstrated that the regional model, with its finer resolution and more comprehensive physics, provides significantly improved results compared to those obtained from the global model. It much more accurately captures the details of the annual cycle and spatial pattern of precipitation. In particular, much more realistic lake-induced precipitation and snowfall patterns downwind of the lakes are predicted. The midcentury projection is analyzed to determine the impact of downscaling on regional climate changes. The emphasis in this final phase of the analysis is on the impact of climate change on winter snowfall in the lee of the lakes. It is found that future changes in lake surface temperature and ice cover under warmer conditions may locally increase snowfall as a result of increased evaporation and the enhanced lake effect.

scholarly journals Assessment of impact of climate change on water resources: a long term analysis of the Great Lakes of North America

2008 ◽  
Vol 12 (1) ◽  
pp. 239-255 ◽  
Author(s):  
E. McBean ◽  
H. Motiee
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Water Resources ◽  
North America ◽  
Great Lakes ◽  
Great Lakes Basin ◽  
Historical Trends ◽  
Global Circulation Models ◽  
The Impact

Abstract. In the threshold of the appearance of global warming from theory to reality, extensive research has focused on predicting the impact of potential climate change on water resources using results from Global Circulation Models (GCMs). This research carries this further by statistical analyses of long term meteorological and hydrological data. Seventy years of historical trends in precipitation, temperature, and streamflows in the Great Lakes of North America are developed using long term regression analyses and Mann-Kendall statistics. The results generated by the two statistical procedures are in agreement and demonstrate that many of these variables are experiencing statistically significant increases over a seven-decade period. The trend lines of streamflows in the three rivers of St. Clair, Niagara and St. Lawrence, and precipitation levels over four of the five Great Lakes, show statistically significant increases in flows and precipitation. Further, precipitation rates as predicted using fitted regression lines are compared with scenarios from GCMs and demonstrate similar forecast predictions for Lake Superior. Trend projections from historical data are higher than GCM predictions for Lakes Michigan/Huron. Significant variability in predictions, as developed from alternative GCMs, is noted. Given the general agreement as derived from very different procedures, predictions extrapolated from historical trends and from GCMs, there is evidence that hydrologic changes particularly for the precipitation in the Great Lakes Basin may be demonstrating influences arising from global warming and climate change.

The Impact of Climate Change on the River Jordan-Lake Kinneret (Israel) Ecosystem

2020 ◽  
pp. 1-12
Author(s):  
Moshe Gophen
Keyword(s):  
Climate Change ◽  
Lake Water ◽  
Regional Climate ◽  
Nitrogen Deficiency ◽  
Regional Climate Change ◽  
Lake Kinneret ◽  
Ecosystem Structure ◽  
Nutrient Inputs ◽  
Lake Water Level ◽  
The Impact

The long-term record of River Jordan-Lake Kinneret ecosystem indicates some significant climate condition changes: water temperature increase, decline in rainfall, and diminishing river discharges and lake water inflows accompanied by a reduction in nitrogen and a slight increase in phosphorus in the Lake upper layers (Epilimnion). Lake Water level decreased, Prolongation of Residence Time was documented, nutrient inputs and dynamics modifications resulting water quality deterioration. As a result of temperature elevation and nitrogen deficiency, the biomass of Peridinium spp significantly reduced and was replaced by Cyanobacterial biomass enhancement. Dryness trend expressed as enhanced frequency of drought seasons initiated an elevation of lake water salinity. It has been suggested that these changes in the phytoplankton community structure are caused by regional climate change. This study evaluates a multi-annual respective approach although the summer is the most critical. The objective of this research is evaluate the background of the ecosystem structure modification aimed at define future potential management design.

scholarly journals Dynamically Downscaled Projections of Lake-Effect Snow in the Great Lakes Basin*,+

2015 ◽  
Vol 28 (4) ◽  
pp. 1661-1684 ◽  
Author(s):  
Michael Notaro ◽  
Val Bennington ◽  
Steve Vavrus
Keyword(s):  
Great Lakes ◽  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Ice Cover ◽  
First Century ◽  
Great Lakes Basin ◽  
Lake Effect ◽  
Lake Model ◽  
Twenty First Century

Abstract Projected changes in lake-effect snowfall by the mid- and late twenty-first century are explored for the Laurentian Great Lakes basin. Simulations from two state-of-the-art global climate models within phase 5 of the Coupled Model Intercomparison Project (CMIP5) are dynamically downscaled according to the representative concentration pathway 8.5 (RCP8.5). The downscaling is performed using the Abdus Salam International Centre for Theoretical Physics (ICTP) Regional Climate Model version 4 (RegCM4) with 25-km grid spacing, interactively coupled to a one-dimensional lake model. Both downscaled models produce atmospheric warming and increased cold-season precipitation. The Great Lakes’ ice cover is projected to dramatically decline and, by the end of the century, become confined to the northern shallow lakeshores during mid-to-late winter. Projected reductions in ice cover and greater dynamically induced wind fetch lead to enhanced lake evaporation and resulting total lake-effect precipitation, although with increased rainfall at the expense of snowfall. A general reduction in the frequency of heavy lake-effect snowstorms is simulated during the twenty-first century, except with increases around Lake Superior by the midcentury when local air temperatures still remain low enough for wintertime precipitation to largely fall in the form of snow. Despite the significant progress made here in elucidating the potential future changes in lake-effect snowstorms across the Great Lakes basin, further research is still needed to downscale a larger ensemble of CMIP5 model simulations, ideally using a higher-resolution, nonhydrostatic regional climate model coupled to a three-dimensional lake model.

Interpreting Results from the NARCCAP and NA-CORDEX Ensembles in the Context of Uncertainty in Regional Climate Change Projections

2018 ◽  
Vol 99 (10) ◽  
pp. 2093-2106 ◽  
Author(s):  
Ambarish V. Karmalkar
Keyword(s):  
Climate Change ◽  
North America ◽  
General Circulation ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Internal Variability ◽  
General Circulation Models ◽  
Eastern United States ◽  
The Impact

AbstractTwo ensembles of dynamically downscaled climate simulations for North America—the North American Regional Climate Change Assessment Program (NARCCAP) and the Coordinated Regional Climate Downscaling Experiment (CORDEX) featuring simulations for North America (NA-CORDEX)—are analyzed to assess the impact of using a small set of global general circulation models (GCMs) and regional climate models (RCMs) on representing uncertainty in regional projections. Selecting GCMs for downscaling based on their equilibrium climate sensitivities is a reasonable strategy, but there are regions where the uncertainty is not fully captured. For instance, the six NA-CORDEX GCMs fail to span the full ranges produced by models in phase 5 of the Coupled Model Intercomparison Project (CMIP5) in summer temperature projections in the western and winter precipitation projections in the eastern United States. Similarly, the four NARCCAP GCMs are overall poor at spanning the full CMIP3 ranges in seasonal temperatures. For the Southeast, the NA-CORDEX GCMs capture the uncertainty in summer but not in winter projections, highlighting one consequence of downscaling a subset of GCMs. Ranges produced by the RCMs are often wider than their driving GCMs but are sensitive to the experimental design. For example, the downscaled projections of summer precipitation are of opposite polarity in two RCM ensembles in some regions. Additionally, the ability of the RCMs to simulate observed temperature trends is affected by the internal variability characteristics of both the RCMs and driving GCMs, and is not systematically related to their historical performance. This has implications for adequately sampling the impact of internal variability on regional trends and for using model performance to identify credible projections. These findings suggest that a multimodel perspective on uncertainties in regional projections is integral to the interpretation of RCM results.

The Role of Ice Cover in Heavy Lake-Effect Snowstorms over the Great Lakes Basin as Simulated by RegCM4

2013 ◽  
Vol 141 (1) ◽  
pp. 148-165 ◽  
Author(s):  
Steve Vavrus ◽  
Michael Notaro ◽  
Azar Zarrin
Keyword(s):  
Great Lakes ◽  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Ice Cover ◽  
Air Pressure ◽  
Great Lakes Basin ◽  
Lake Effect ◽  
The Impact

Abstract A 20-km regional climate model, the Abdus Salam International Centre for Theoretical Physics Regional Climate Model version 4 (ICTP RegCM4), is employed to investigate heavy lake-effect snowfall (HLES) over the Great Lakes Basin and the role of ice cover in regulating these events. When coupled to a lake model and driven with atmospheric reanalysis data between 1976 and 2002, RegCM4 reproduces the major characteristics of HLES. The influence of lake ice cover on HLES is investigated through 10 case studies (2 per Great Lake), in which a simulated heavy lake-effect event is compared with a companion simulation having 100% ice cover imposed on one or all of the Great Lakes. These experiments quantify the impact of ice cover on downstream snowfall and demonstrate that Lake Superior has the strongest, most widespread influence on heavy snowfall and Lake Ontario the least. Ice cover strongly affects a wide range of atmospheric variables above and downstream of lakes during HLES, including snowfall, surface energy fluxes, wind speed, temperature, moisture, clouds, and air pressure. Averaged among the 10 events, complete ice coverage causes major reductions in lake-effect snowfall (>80%) and turbulent heat fluxes over the lakes (>90%), less low cloudiness, lower temperatures, and higher air pressure. Another important consequence is a consistent weakening (30%–40%) of lower-tropospheric winds over the lakes when completely frozen. This momentum reduction further decreases over-lake evaporation and weakens downstream wind convergence, thus mitigating lake-effect snowfall. This finding suggests a secondary, dynamical mechanism by which ice cover affects downstream snowfall during HLES events, in addition to the more widely recognized thermodynamic influence.

Convection-Permitting Regional Climate Simulations over North America

2020 ◽  
Author(s):  
Changhai Liu ◽  
Kyoko Ikeda ◽  
Roy Rasmussen
Keyword(s):  
Climate Change ◽  
North America ◽  
Water Cycle ◽  
Regional Climate ◽  
Water System ◽  
Wrf Model ◽  
Future Climate ◽  
Convective Precipitation ◽  
Historical Simulation ◽  
The Impact

<p>The NCAR Water System Program has been striving to improve the representation of the water cycle and its future changes in both regional and global models during the past decade. One of our efforts is conducting continental-scale convection-permitting simulations of the current and future climate of North America using the WRF model based atmospheric-hydrological coupling system. The major science objectives of these simulations are: 1) to evaluate the capability of convection-permitting WRF model in capturing orographic precipitation and snow mass balance over the western mountains of North America and convective precipitation in the eastern part of the continent; 2) to assess future changes in seasonal snowfall and snowpack and associated surface hydrological cycles under the CMIP5-projected global warming; 3) to investigate water cycle changes in response to climate warming, including the summertime convective precipitation and associated mesoscale convective storm tracks; and 4) to examine the impact of climate change on severe weather over North America. As such, two phases of convection-permitting climate modeling have been undertaken using 4-km horizontal grid spacing covering most of North America.</p><p>The phase-one effort involves two 13-year simulations as reported in Liu et al. (2017): 1) a historical simulation with initial and boundary conditions from ERA-interim, and 2) a future climate sensitivity simulation, called pseudo-global warming (PGW), with modified reanalysis-derived initial and boundary conditions by adding the CMIP5 ensemble-mean projected climate change. These WRF-downscaled climate change simulations provide a unique high-resolution dataset to the community for studying one possible scenario of regional climate changes and impacts.</p><p>Recognizing that only the thermodynamic future climate impacts can be adequately addressed in the PGW approach, the NCAR Water System team has started conducting a second set (phase II) of current and future simulations at 4-km grid spacing over North America. In these simulations, the WRF model is forced using the weather perturbations derived from the NCAR CESM model 6-hourly output plus the reanalysis-based bias-corrected CMIP5 ensemble mean climate as detailed in Dai et al. (2017). The model domain is also expanded northward to include Canada and the Canadian Arctic. Because storm track changes are permitted, these simulations complement the previous PGW simulations, allowing us to address the impact of dynamic changes in the future warmer climate. We will present some preliminary analysis results of these simulations, with focus on the evaluation of the historical simulation and the added value of convection-permitting resolution and mean climate bias corrections.</p>

scholarly journals Climate Projections over the Great Lakes Region: Using Two-way Coupling of a Regional Climate Model with a 3-D Lake Model

2022 ◽  
Author(s):  
Pengfei Xue ◽  
Xinyu Ye ◽  
Jeremy S. Pal ◽  
Philip Y. Chu ◽  
Miraj B. Kayastha ◽  
...  
Keyword(s):  
Climate Change ◽  
Great Lakes ◽  
Regional Climate Model ◽  
21St Century ◽  
Climate Model ◽  
Regional Climate ◽  
Ensemble Average ◽  
Lake Surface ◽  
Lake Model ◽  
Rcp 8.5

Abstract. Warming trends of the Laurentian Great Lakes and surrounding areas have been observed in recent decades, and concerns continue to rise about the pace and pattern of future climate change over the world’s largest freshwater system. To date, many regional climate models used for the Great Lakes projection either neglected the lake-atmosphere interactions or only coupled with 1-D column lake models to represent the lake hydrodynamics. The study presents the Great Lakes climate change projection that has employed the two-way coupling of a regional climate model with a 3-D lake model (GLARM) to resolve 3-D hydrodynamics important for large lakes. Using the three carefully selected CMIP5 AOGCMS, we show that the GLARM ensemble average substantially reduces the surface air temperature and precipitation biases of the driving AOGCM ensemble average in present-day climate simulations. The improvements are not only displayed from the atmospheric perspective but also evidenced in accurate simulations of lake surface temperature, and ice coverage and duration. After that, we present the GLARM projected climate change for the mid-21st century (2030–2049) and the late century (2080–2099) for the RCP4.5 and RCP8.5. Under RCP 8.5, the Great Lakes basin is projected to warm by 1.3–2.2 °C by the mid-21st century and 4.0–4.9 °C by the end of the century relative to the early-century (2000–2019). Moderate mitigation (RCP 4.5) reduces the mid-century warming to 0.8–1.9 °C and late-century warming to 1.8–2.7 °C. Annual precipitation in GLARM is projected to increase for the entire basin, varying from −0.4 % to 10.5 % during the mid-century and 1.2 % to 28.5 % during the late-century under different scenarios and simulations. The most significant increases are projected in spring and early summer when current precipitation is highest and little increase in winter when it is lowest. Lake surface temperatures (LSTs) are also projected to increase across the five lakes in all of the simulations, but with strong seasonal and spatial heterogeneities. The most significant LST increase will occur in Lake Superior. The strongest warming was projected in spring, followed by strong summer warming, suggesting earlier and more intense stratification in the future. In contrast, a relatively smaller increase in LSTs during fall and winter are projected with heat transfer to the deepwater due to strong mixing and energy required for ice melting. Correspondingly, the highest monthly mean ice cover is projected to be 3–6 % and 8–20 % across the lakes by the end of the century in RCP 8.5 and RCP 4.5, respectively. In the coastal regions, ice duration will decrease by up to 30–50 days.

scholarly journals Climate Change Controls Phosphorus Transport from the Watershed into Lake Kinneret (Israel)

2021 ◽  
Author(s):  
Moshe Gophen
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Lake Kinneret ◽  
Phosphorus Transport ◽  
Efficient Management ◽  
Hula Valley ◽  
Reclamation Project ◽  
The Impact

AbstractPart of the Kinneret watershed, the Hula Valley, was modified from wetlands – shallow lake for agricultural cultivation. Enhancement of nutrient fluxes into Lake Kinneret was predicted. Therefore, a reclamation project was implemented and eco-tourism partly replaced agriculture. Since the mid-1980s, regional climate change has been documented. Statistical evaluation of long-term records of TP (Total Phosphorus) concentrations in headwaters and potential resources in the Hula Valley was carried out to identify efficient management design targets. Significant correlation between major headwater river discharge and TP concentration was indicated, whilst the impact of external fertilizer loads and 50,000 winter migratory cranes was probably negligible. Nevertheless, confirmed severe bdamage to agricultural crops carried out by cranes led to their maximal deportation and optimization of their feeding policy. Consequently, the continuation of the present management is recommended.

scholarly journals Environmental Change Threatens Freshwater Insect Communities in Northwest Africa: A Meta-Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Nils Kaczmarek ◽  
Ralf B. Schäfer ◽  
Elisabeth Berger
Keyword(s):  
Climate Change ◽  
Water Temperature ◽  
Negative Binomial ◽  
Small Body ◽  
Future Research ◽  
Insect Communities ◽  
Data Set ◽  
Temperature Conductivity ◽  
Northwest Africa ◽  
The Impact

A climatic shift from temperate to arid conditions is predicted for Northwest Africa. Water temperature, salinity, and river intermittency are likely to increase, which may impact freshwater communities, ecosystem functioning, and related ecosystem services. Quantitative data and information on the impact of climate change on insect communities (e.g., richness, taxonomic and trait composition) are still scarce for Northwest Africa. In this study, we extracted information on freshwater insect occurrence and environmental variables in Northwest Africa from the results of a literature search to study potential consequences of changing climatic conditions for these communities. Our data set covered 96 families in 165 sites in Morocco and Algeria. We quantified the impact of several explanatoryvariables (climate, altitude, water temperature, conductivity, intermittency, flow, aridity, dams, and land cover) on richness, taxonomic and functional trait composition using negative binomial regression models and constrained ordination. Family richness in arid sites was on average 37 % lower than in temperate sites in association with flow, river regulation, cropland extent, conductivity, altitude, and water temperature. With 36 % of the studied temperate sites predicted to turn arid by the end of the century, a loss of insect families can be predicted for Northwest Africa, mainly affecting species adapted to temperate environments. Resistance and resilience traits such as small body size, aerial dispersal, and air breathing promote survival in arid climates. Future research should report insect occurrences on species level to allow for better predictions on climate change effects.

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