scholarly journals Physical and biogeochemical impacts of RCP8.5 scenario in the Peru upwelling system

2020 ◽  
Author(s):  
Vincent Echevin ◽  
Manon Gévaudan ◽  
Dante Espinoza-Morriberon ◽  
Jorge Tam ◽  
Olivier Aumont ◽  
...  
Keyword(s):  
Climate Change ◽  
Coastal Upwelling ◽  
Current System ◽  
Regional Climate ◽  
Physical Parameters ◽  
Climate Projections ◽  
Surface Cooling ◽  
Humboldt Current ◽  
Upwelling System ◽  
The Impact

Abstract. The northern Humboldt current system (NHCS or Peru upwelling system) sustains the world's largest small pelagic fishery. While a nearshore surface cooling has been observed off southern Peru in recent decades, there is still considerable debate on the impact of climate change on the regional ecosystem. This calls for more accurate regional climate projections of the 21st century, using adapted tools such as regional eddy-resolving coupled biophysical models. In this study 3 coarse-grid Earth System Models (ESMs) from the Coupled Model Intercomparison Project (CMIP5) are selected based on their biogeochemical biases upstream of the NHCS and simulations for the so-called business-as-usual RCP8.5 climate scenario are dynamically downscaled at 10 km resolution in the NHCS. The impact of regional climate change on temperature, coastal upwelling, nutrient content, deoxygenation and the planktonic ecosystem is documented. We find that the downscaling approach allows to correct major physical and biogeochemical biases of the ESMs. All regional simulations display a surface warming regardless of the coastal upwelling trends. Contrasted evolutions of the NHCS oxygen minimum zone and enhanced stratification of phytoplankton are found in the coastal region. Whereas trends of downscaled physical parameters are consistent with ESM trends, downscaled biogeochemical trends differ markedly. These results suggest that more realism of the ESMs is needed in the eastern equatorial Pacific to gain robustness in the projection of regional trends in the NHCS.

scholarly journals Physical and biogeochemical impacts of RCP8.5 scenario in the Peru upwelling system

2020 ◽  
Vol 17 (12) ◽  
pp. 3317-3341
Author(s):  
Vincent Echevin ◽  
Manon Gévaudan ◽  
Dante Espinoza-Morriberón ◽  
Jorge Tam ◽  
Olivier Aumont ◽  
...  
Keyword(s):  
Climate Change ◽  
Coastal Upwelling ◽  
Current System ◽  
Regional Climate ◽  
Physical Parameters ◽  
Climate Projections ◽  
Surface Cooling ◽  
Humboldt Current ◽  
Upwelling System ◽  
The Impact

Abstract. The northern Humboldt Current system (NHCS or Peru upwelling system) sustains the world's largest small pelagic fishery. While a nearshore surface cooling has been observed off southern Peru in recent decades, there is still considerable debate on the impact of climate change on the regional ecosystem. This calls for more accurate regional climate projections of the 21st century, using adapted tools such as regional eddy-resolving coupled biophysical models. In this study three coarse-grid Earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are selected based on their biogeochemical biases upstream of the NHCS, and simulations for the RCP8.5 climate scenario are dynamically downscaled at ∼12 km resolution in the NHCS. The impact of regional climate change on temperature, coastal upwelling, nutrient content, deoxygenation, and the planktonic ecosystem is documented. We find that the downscaling approach allows us to correct major physical and biogeochemical biases of the ESMs. All regional simulations display a surface warming regardless of the coastal upwelling trends. Contrasted evolutions of the NHCS oxygen minimum zone and enhanced stratification of phytoplankton are found in the coastal region. Whereas trends of downscaled physical parameters are consistent with ESM trends, downscaled biogeochemical trends differ markedly. These results suggest that more realism of the ESM circulation, nutrient, and dissolved oxygen fields is needed in the eastern equatorial Pacific to gain robustness in the projection of regional trends in the NHCS.

scholarly journals Modeling the impact of climate change on mussel aquaculture in a coastal upwelling system: A critical assessment

2021 ◽  
Vol 775 ◽  
pp. 145020
Author(s):  
Isabel Fuentes-Santos ◽  
Uxío Labarta ◽  
María José Fernández-Reiriz ◽  
Susan Kay ◽  
Solfrid Sætre Hjøllo ◽  
...  
Keyword(s):  
Climate Change ◽  
Coastal Upwelling ◽  
Critical Assessment ◽  
Impact Of Climate Change ◽  
Upwelling System ◽  
System A ◽  
The Impact

scholarly journals Climate Perspectives in the Intra–Americas Seas

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 959
Author(s):  
Ana María Durán-Quesada ◽  
Rogert Sorí ◽  
Paulina Ordoñez ◽  
Luis Gimeno
Keyword(s):  
Climate Change ◽  
Extreme Events ◽  
Large Scale ◽  
Negative Impact ◽  
Current Knowledge ◽  
Regional Climate ◽  
Climate Projections ◽  
Economic Activities ◽  
Weather And Climate ◽  
The Impact

The Intra–Americas Seas region is known for its relevance to air–sea interaction processes, the contrast between large water masses and a relatively small continental area, and the occurrence of extreme events. The differing weather systems and the influence of variability at different spatio–temporal scales is a characteristic feature of the region. The impact of hydro–meteorological extreme events has played a huge importance for regional livelihood, having a mostly negative impact on socioeconomics. The frequency and intensity of heavy rainfall events and droughts are often discussed in terms of their impact on economic activities and access to water. Furthermore, future climate projections suggest that warming scenarios are likely to increase the frequency and intensity of extreme events, which poses a major threat to vulnerable communities. In a region where the economy is largely dependent on agriculture and the population is exposed to the impact of extremes, understanding the climate system is key to informed policymaking and management plans. A wealth of knowledge has been published on regional weather and climate, with a majority of studies focusing on specific components of the system. This study aims to provide an integral overview of regional weather and climate suitable for a wider community. Following the presentation of the general features of the region, a large scale is introduced outlining the main structures that affect regional climate. The most relevant climate features are briefly described, focusing on sea surface temperature, low–level circulation, and rainfall patterns. The impact of climate variability at the intra–seasonal, inter–annual, decadal, and multi–decadal scales is discussed. Climate change is considered in the regional context, based on current knowledge for natural and anthropogenic climate change. The present challenges in regional weather and climate studies have also been included in the concluding sections of this review. The overarching aim of this work is to leverage information that may be transferred efficiently to support decision–making processes and provide a solid foundation on regional weather and climate for professionals from different backgrounds.

scholarly journals Assessment of the impacts of climate change on maize production in the Wami Ruvu basin of Tanzania

2016 ◽  
Vol 8 (1) ◽  
pp. 142-164 ◽  
Author(s):  
Philbert Luhunga ◽  
Ladslaus Chang'a ◽  
George Djolov
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Regional Climate ◽  
Climate Projections ◽  
Intergovernmental Panel ◽  
Lower Altitude ◽  
Rcp 8.5 ◽  
Maize Yields ◽  
The Impact ◽  
Impacts Of Climate Change

The IPCC (Intergovernmental Panel on Climate Change) assessment reports confirm that climate change will hit developing countries the hardest. Adaption is on the agenda of many countries around the world. However, before devising adaption strategies, it is crucial to assess and understand the impacts of climate change at regional and local scales. In this study, the impact of climate change on rain-fed maize (Zea mays) production in the Wami-Ruvu basin of Tanzania was evaluated using the Decision Support System for Agro-technological Transfer. The model was fed with daily minimum and maximum temperatures, rainfall and solar radiation for current climate conditions (1971–2000) as well as future climate projections (2010–2099) for two Representative Concentration Pathways: RCP 4.5 and RCP 8.5. These data were derived from three high-resolution regional climate models, used in the Coordinated Regional Climate Downscaling Experiment program. Results showed that due to climate change future maize yields over the Wami-Ruvu basin will slightly increase relative to the baseline during the current century under RCP 4.5 and RCP 8.5. However, maize yields will decline in the mid and end centuries. The spatial distribution showed that high decline in maize yields are projected over lower altitude regions due to projected increase in temperatures in those areas.

scholarly journals Storyline approach to the construction of regional climate change information

2019 ◽  
Vol 475 (2225) ◽  
pp. 20190013 ◽  
Author(s):  
Theodore G. Shepherd
Keyword(s):  
Climate Change ◽  
Atmospheric Circulation ◽  
Regional Climate ◽  
Regional Scale ◽  
Regional Climate Change ◽  
Climate Impacts ◽  
Climate Projections ◽  
Ethical Implications ◽  
Climate Change Information ◽  
The Impact

Climate science seeks to make statements of confidence about what has happened, and what will happen (conditional on scenario). The approach is effective for the global, thermodynamic aspects of climate change, but is ineffective when it comes to aspects of climate change related to atmospheric circulation, which are highly uncertain. Yet, atmospheric circulation strongly mediates climate impacts at the regional scale. In this way, the confidence framework, which focuses on avoiding type 1 errors (false alarms), raises the prospect of committing type 2 errors (missed warnings). This has ethical implications. At the regional scale, however, where information on climate change has to be combined with many other factors affecting vulnerability and exposure—most of which are highly uncertain—the societally relevant question is not ‘What will happen?’ but rather ‘What is the impact of particular actions under an uncertain regional climate change?’ This reframing of the question can cut the Gordian knot of regional climate change information, provided one distinguishes between epistemic and aleatoric uncertainties—something that is generally not done in climate projections. It is argued that the storyline approach to climate change—the identification of physically self-consistent, plausible pathways—has the potential to accomplish precisely this.

Is Institutional Democracy a Good Proxy for Model Independence?

2016 ◽  
Vol 29 (23) ◽  
pp. 8301-8316 ◽  
Author(s):  
Martin Leduc ◽  
René Laprise ◽  
Ramón de Elía ◽  
Leo Šeparović
Keyword(s):  
Climate Change ◽  
Model Comparison ◽  
Climate Models ◽  
Regional Climate ◽  
Burden Of Proof ◽  
Climate Projections ◽  
Climate Change Projections ◽  
Cross Model ◽  
Structural Differences ◽  
The Impact

Abstract Climate models developed within a given research group or institution are prone to share structural similarities, which may induce resembling features in their simulations of the earth’s climate. This assertion, known as the “same-center hypothesis,” is investigated here using a subsample of CMIP3 climate projections constructed by retaining only the models originating from institutions that provided more than one model (or model version). The contributions of individual modeling centers to this ensemble are first presented in terms of climate change projections. A metric for climate change disagreement is then defined to analyze the impact of typical structural differences (such as resolution, parameterizations, or even entire atmosphere and ocean components) on regional climate projections. This metric is compared to a present climate performance metric (correlation of error patterns) within a cross-model comparison framework in terms of their abilities to identify the same-center models. Overall, structural differences between the pairs of same-center models have a stronger impact on climate change projections than on how models reproduce the observed climate. The same-center criterion is used to detect agreements that might be attributable to model similarities and thus that should not be interpreted as implying greater confidence in a given result. It is proposed that such noninformative agreements should be discarded from the ensemble, unless evidence shows that these models can be assumed to be independent. Since this burden of proof is not generally met by the centers participating in a multimodel ensemble, the authors propose an ensemble-weighting scheme based on the assumption of institutional democracy to prevent overconfidence in climate change projections.

scholarly journals A Projection of the Wind Energy in the Black Sea along the 21st Century

2019 ◽  
Vol 103 ◽  
pp. 01005
Author(s):  
Liliana Rusu
Keyword(s):  
Climate Change ◽  
Wind Energy ◽  
Wind Power ◽  
Black Sea ◽  
Regional Climate ◽  
The Black Sea ◽  
Climate Projections ◽  
Wind Fields ◽  
The Future ◽  
The Impact

The objective of this study is to assess the future wind power potential in the Black Sea based on the wind fields provided by the most recent regional climate projections achieved in the framework of EURO-CORDEX project. The climate change impacts on the wind speed magnitude will bring changes in the local wind power generation. From this perspective, changes in the wind power potential along the 21st century in some reference locations of the Black Sea basin are investigated under the RCP4.5 scenario. The recent wind power conditions for a 30-year period (1976-2005) are assessed based on the results provided by the same RCM (Regional Climate Model) used to generate the future climate projections of the wind fields. The impact of the climate change on the future wind power potential is evaluated by comparisons between historical data and near-future (2021-2050) and more distant future (2071-2100) projections. Under the scenario considered, an increase of the mean wind power was observed until the middle of the 21st century, followed by a small decrease. From the seasonal analysis resulted that, in the reference points located on the western side, the projection of the wind energy in winter time suggests an increase until the end of the century. On the other hand, the linear regressions adjusted to the annual means do not indicate a significant trend.

Balanced subsampling of future regional climate ensembles of opportunity

2020 ◽  
Author(s):  
Jesús Fernández ◽  
María Dolores Frías
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Regional Climate ◽  
National Level ◽  
Future Climate Change ◽  
Climate Projections ◽  
Climate Modelling ◽  
Model Intercomparison ◽  
Climate Change Projections ◽  
The Impact

<p>International model intercomparison initiatives, such as CORDEX or CMIP5, along with several relatively recent projects at international and national level, provide a wealth of model simulations of future regional climate. In a recent work, Fernandez et al (2019) collected 196 different future climate change projections over Spain, considering data from ENSEMBLES, ESCENA, EURO- and Med-CORDEX, along with their driving global climate projections from CMIP3 and CMIP5. This ensemble mixed different multi-model initiatives in an ensemble of opportunity, in the sense that it does not respond to any scientific design beyond the exploration of multi-model uncertainty. This ensemble of opportunity is not only the result of the mixture of different initiatives, but also responds to the lack of a balanced experimental design within most of the initiatives. Many of the initiatives -especially those unfunded, such as CORDEX- are carried out on a voluntary basis, with no strong constraint in the global climate models (GCMs) used as boundary conditions or in the number of contributing members per regional climate model (RCM).</p><p>Fernandez et al (2019) found in this ensemble a strong influence of the driving GCM on the regional climate change signal, along with favored GCMs, selected by many regional climate modelling groups to the detriment of GCMs publishing their output later or not at all. In this work, we quantitatively assess the impact of unbalanced GCM-RCM ensembles. For this purpose, we subsampled the ensemble of opportunity to obtain balanced sets of members according to different “what-if” situations: What if all RCMs had contributed a single member to the ensemble? What if each GCM had been dynamically downscaled only once? What if a given GCM/RCM had not contributed to the ensemble? For each hypothesis, there are a number of alternative sub-ensembles, which are used to evaluate uncertainty.</p><p><strong>Acknowledgement:</strong></p><p>This work is partially funded by the Spanish government through MINECO/FEDER co-funded projects INSIGNIA (CGL2016-79210-R) and MULTI-SDM (CGL2015-66583-R). </p><p><strong>References:</strong></p><p>Fernández, J., et al. (2019) Consistency of climate change projections from multiple global and regional model intercomparison projects. Clim Dyn 52:1139. https://doi.org/10.1007/s00382-018-4181-8</p>

scholarly journals Insight into anthropogenic forcing on coastal upwelling off south-central Chile

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Catalina Aguirre ◽  
Sebastián García-Loyola ◽  
Giovanni Testa ◽  
Diego Silva ◽  
Laura Farías
Keyword(s):  
Surface Waters ◽  
Coastal Upwelling ◽  
Current System ◽  
Mixed Layer Depth ◽  
Positive Trend ◽  
Surface Cooling ◽  
Humboldt Current ◽  
Southern Boundary ◽  
Global Circulation Models ◽  
South Central

Coastal upwelling systems off the coasts of Peru and Chile are among the most productive marine ecosystems in the world, sustaining a significant percentage of global primary production and fishery yields. Seasonal and interannual variability in these systems has been relatively well documented; however, an understanding of recent trends and the influence of climate change on marine processes such as surface cooling and primary productivity is limited. This study presents evidence that winds favorable to upwelling have increased within the southern boundary of the Humboldt Current System (35°–42°S) in recent decades. This trend is consistent with a poleward movement of the influence of the Southeast Pacific Anticyclone and resembles the spatial pattern projected by Global Circulation Models for warming scenarios. Chlorophyll a levels (from 2002 to present) determined by satellite and field-based time-series observations show a positive trend, mainly in austral spring–summer (December–January–February), potentially explained by observed increments in nutrient flux towards surface waters and photosynthetically active radiation. Both parameters appear to respond to alongshore wind stress and cloud cover in the latitudinal range of 35°S to 42°S. In addition, net annual deepening of the mixed layer depth is estimated using density and temperature profiles. Changes in this depth are associated with increasing winds and may explain cooler, more saline, and more productive surface waters, with the latter potentially causing fluctuations in dissolved oxygen and other gases, such as nitrous oxide, sensitive to changes in oxygenation. We argue that these recent changes represent, at least in part, a regional manifestation of the Anthropocene along the Chilean coast.

scholarly journals Using statistical models to explore ensemble uncertainty in climate impact studies: the example of air pollution in Europe

2016 ◽  
Vol 16 (4) ◽  
pp. 2559-2574 ◽  
Author(s):  
Vincent E. P. Lemaire ◽  
Augustin Colette ◽  
Laurent Menut
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Quality ◽  
Statistical Model ◽  
Eastern Europe ◽  
Statistical Models ◽  
Regional Climate ◽  
Northern Italy ◽  
Climate Projections ◽  
The Impact

Abstract. Because of its sensitivity to unfavorable weather patterns, air pollution is sensitive to climate change so that, in the future, a climate penalty could jeopardize the expected efficiency of air pollution mitigation measures. A common method to assess the impact of climate on air quality consists in implementing chemistry-transport models forced by climate projections. However, the computing cost of such methods requires optimizing ensemble exploration techniques. By using a training data set from a deterministic projection of climate and air quality over Europe, we identified the main meteorological drivers of air quality for eight regions in Europe and developed statistical models that could be used to predict air pollutant concentrations. The evolution of the key climate variables driving either particulate or gaseous pollution allows selecting the members of the EuroCordex ensemble of regional climate projections that should be used in priority for future air quality projections (CanESM2/RCA4; CNRM-CM5-LR/RCA4 and CSIRO-Mk3-6-0/RCA4 and MPI-ESM-LR/CCLM following the EuroCordex terminology). After having tested the validity of the statistical model in predictive mode, we can provide ranges of uncertainty attributed to the spread of the regional climate projection ensemble by the end of the century (2071–2100) for the RCP8.5. In the three regions where the statistical model of the impact of climate change on PM2.5 offers satisfactory performances, we find a climate benefit (a decrease of PM2.5 concentrations under future climate) of −1.08 (±0.21), −1.03 (±0.32), −0.83 (±0.14) µg m−3, for respectively Eastern Europe, Mid-Europe and Northern Italy. In the British-Irish Isles, Scandinavia, France, the Iberian Peninsula and the Mediterranean, the statistical model is not considered skillful enough to draw any conclusion for PM2.5. In Eastern Europe, France, the Iberian Peninsula, Mid-Europe and Northern Italy, the statistical model of the impact of climate change on ozone was considered satisfactory and it confirms the climate penalty bearing upon ozone of 10.51 (±3.06), 11.70 (±3.63), 11.53 (±1.55), 9.86 (±4.41), 4.82 (±1.79) µg m−3, respectively. In the British-Irish Isles, Scandinavia and the Mediterranean, the skill of the statistical model was not considered robust enough to draw any conclusion for ozone pollution.

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