scholarly journals Phase-Adjustment Mechanism during Enso Cycles under Sun-Moon Gravitation

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Climate Models ◽  
Adjustment Mechanism ◽  
Phase Adjustment ◽  
In Series ◽  
Climate Systems ◽  
Climate Studies ◽  
Oceanic Currents

Climate predictions often fail when climate starts to adjust, with uncertainties increasing with the length of prediction windows where observations are no longer available to contain the missed dynamics and correct climate models. I introduced the missed dynamic astronomy factor (Sun-Moon gravitation) into climate studies and found it producing phase adjustments during ENSO cycles through seasonally changing the atmospheric and oceanic circulations, besides producing structural atmospheric-oceanic currents, climatepaleoclimate variations, and initiating and maintaining planetary rotations that play key roles in weather-climate systems, as reported here in series after concerned miscellaneous equations and their derivations were published in [1,2].

scholarly journals Reference crop evapotranspiration database in Spain (1961–2014)

2019 ◽  
Vol 11 (4) ◽  
pp. 1917-1930 ◽  
Author(s):  
Miquel Tomas-Burguera ◽  
Sergio M. Vicente-Serrano ◽  
Santiago Beguería ◽  
Fergus Reig ◽  
Borja Latorre
Keyword(s):  
Climate Models ◽  
Severity Index ◽  
Important Variable ◽  
Drought Indices ◽  
Drought Severity ◽  
Climate Variables ◽  
Evaporative Demand ◽  
Research Areas ◽  
Climate Studies ◽  
Reference Crop

Abstract. Obtaining climate grids describing distinct variables is important for developing better climate studies. These grids are also useful products for other researchers and end users. The atmospheric evaporative demand (AED) may be measured in terms of the reference evapotranspiration (ETo), a key variable for understanding water and energy terrestrial balances and an important variable in climatology, hydrology and agronomy. Despite its importance, the calculation of ETo is not commonly undertaken, mainly because datasets consisting of a high number of climate variables are required and some of the required variables are not commonly available. To address this problem, a strategy based on the spatial interpolation of climate variables prior to the calculation of ETo using FAO-56 Penman–Monteith equation was followed to obtain an ETo database for continental Spain and the Balearic Islands, covering the 1961–2014 period at a spatial resolution of 1.1 km and at a weekly temporal resolution. In this database, values for the radiative and aerodynamic components as well as the estimated uncertainty related to ETo were also provided. This database is available for download in the Network Common Data Form (netCDF) at https://doi.org/10.20350/digitalCSIC/8615 (Tomas-Burguera et al., 2019). A map visualization tool (http://speto.csic.es, last access: 10 December 2019) is available to help users download the data corresponding to one specific point in comma-separated values (csv) format. A relevant number of research areas could take advantage of this database. For example, (i) studies of the Budyko curve, which relates rainfall data to the evapotranspiration and AED at the watershed scale, (ii) calculations of drought indices using AED data, such as the Standardized Precipitation–Evapotranspiration Index (SPEI) or Palmer Drought Severity Index (PDSI), (iii) agroclimatic studies related to irrigation requirements, (iv) validation of climate models' water and energy balance, and (v) studies of the impacts of climate change in terms of the AED.

scholarly journals Performance of the Adriatic Sea and Coast (AdriSC) climate component – a COAWST V3.3-based coupled atmosphere–ocean modelling suite: atmospheric dataset

2021 ◽  
Vol 14 (6) ◽  
pp. 3995-4017
Author(s):  
Cléa Denamiel ◽  
Petra Pranić ◽  
Damir Ivanković ◽  
Iva Tojčić ◽  
Ivica Vilibić
Keyword(s):  
Climate Models ◽  
Thermohaline Circulation ◽  
Climate Model ◽  
Adriatic Sea ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Evaluation Study ◽  
Ocean Model ◽  
Climate Studies

Abstract. In this evaluation study, the coupled atmosphere–ocean Adriatic Sea and Coast (AdriSC) climate model, which was implemented to carry out 31-year evaluation and climate projection simulations in the Adriatic and northern Ionian seas, is briefly presented. The kilometre-scale AdriSC atmospheric results, derived with the Weather Research and Forecasting (WRF) 3 km model for the 1987–2017 period, are then thoroughly compared to a comprehensive publicly and freely available observational dataset. The evaluation shows that overall, except for the summer surface temperatures, which are systematically underestimated, the AdriSC WRF 3 km model has a far better capacity to reproduce surface climate variables (and particularly the rain) than the WRF regional climate models at 0.11∘ resolution. In addition, several spurious data have been found in both gridded products and in situ measurements, which thus should be used with care in the Adriatic region for climate studies at local and regional scales. Long-term simulations with the AdriSC climate model, which couples the WRF 3 km model with a 1 km ocean model, might thus be a new avenue to substantially improve the reproduction, at the climate scale, of the Adriatic Sea dynamics driving the Eastern Mediterranean thermohaline circulation. As such it may also provide new standards for climate studies of orographically developed coastal regions in general.

scholarly journals An evaluation of ozone dry deposition in global scale chemistry climate models

2015 ◽  
Vol 15 (11) ◽  
pp. 6419-6436 ◽  
Author(s):  
C. Hardacre ◽  
O. Wild ◽  
L. Emberson
Keyword(s):  
Dry Deposition ◽  
Climate Models ◽  
Model Development ◽  
Critical Evaluation ◽  
Global Scale ◽  
Systematic Bias ◽  
Deposition Fluxes ◽  
In Series ◽  
Underlying Processes ◽  
Earth System Models

Abstract. Dry deposition to the Earth's surface is an important process from both an atmospheric and biospheric perspective. Dry deposition controls the atmospheric abundance of many compounds as well as their input to vegetative surfaces, thus linking the atmosphere and biosphere. In many atmospheric and Earth system models it is represented using "resistance in series" schemes developed in the 1980s. These methods have remained relatively unchanged since their development and do not take into account more recent understanding of the underlying processes that have been gained through field and laboratory based studies. In this study we compare dry deposition of ozone across 15 models which contributed to the TF HTAP model intercomparison to identify where differences occur. We compare modelled dry deposition of ozone to measurements made at a variety of locations in Europe and North America, noting differences of up to a factor of two but no clear systematic bias over the sites examined. We identify a number of measures that are needed to provide a more critical evaluation of dry deposition fluxes and advance model development.

scholarly journals Reference crop evapotranspiration database in Spain (1961–2014)

2019 ◽  
Author(s):  
Miquel Tomas-Burguera ◽  
Sergio M. Vicente-Serrano ◽  
Santiago Beguería ◽  
Fergus Reig ◽  
Borja Latorre
Keyword(s):  
Spatial Interpolation ◽  
Climate Models ◽  
Drought Indices ◽  
Watershed Scale ◽  
Climate Variables ◽  
Evaporative Demand ◽  
Reference Crop Evapotranspiration ◽  
Climate Studies ◽  
Reference Crop ◽  
Impacts Of Climate Change

Abstract. Obtaining climate grids for distinct variables is of high importance to develop better climate studies, but also to offer usable products for other researchers and to end users. As a measure of atmospheric evaporative demand (AED), reference evapotranspiration (ETo) is a key variable for understanding both water and energy terrestrial balances, being important for climatology, hydrology and agronomy. In spite of its importance, the calculation of ETo is not very common, mainly because data of a high number of climate variables are required, and some of them are not commonly available. To solve this problem, a strategy based on the spatial interpolation of climate variables previous to calculation of ETo using FAO-56 Penman-Monteith was followed to obtain an ETo database for Continental Spain and Balearic Islands covering the 1961–2014 period at a spatial resolution of 1.1 km and at weekly temporal resolution. In this database, values for the radiative and aerodynamic components as well as the estimated uncertainty related with ETo are also provided. This database is available to download in Network Common Data Form (netcdf) format at https://doi.org/10.20350/digitalCSIC/8615 (Tomas-Burguera et al., 2019), and a map visualization tool (http://speto.csic.es) is also available to help users to download data of one specific point in comma-separated values (csv) format. A relevant number of research ares could take advantage of this database. Providing only some examples: i) the study of budyko curve, which relates rainfall data with evapotranspiration and AED at watershed scale; ii) the calculation of drought indices using AED data, such as SPEI or PDSI; iii) agroclimatic studies related with irrigation requirement; iv) validation of Climate Models water and energy balance; v) the study of the impacts of climate change in AED.

scholarly journals Performance of the Adriatic Sea and Coast (AdriSC) climate component – a COAWST V3.3-based coupled atmosphere-ocean modelling suite: atmospheric part 

2021 ◽  
Author(s):  
Cléa Denamiel ◽  
Petra Pranić ◽  
Damir Ivanković ◽  
Iva Tojčić ◽  
Ivica Vilibić
Keyword(s):  
Climate Models ◽  
Thermohaline Circulation ◽  
Climate Model ◽  
Adriatic Sea ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Evaluation Study ◽  
Ocean Model ◽  
Climate Studies

Abstract. In this evaluation study, the coupled atmosphere-ocean Adriatic Sea and Coast (AdriSC) climate model, which was implemented to carry out 31-year long evaluation and climate projection simulations in the Adriatic and northern Ionian seas, is briefly presented. The kilometre-scale AdriSC atmospheric results, derived with the Weather Research and Forecasting (WRF) 3-km model for the 1987–2017 period, are then thoroughly compared to a comprehensive publicly and freely available observational dataset. The evaluation shows that overall, except for the summer surface temperatures which are systematically underestimated, the AdriSC WRF 3-km model has a far better capacity to reproduce the surface climate variables (and particularly the rain) than the WRF regional climate models at 0.11° of resolution. In addition, several spurious data have been found in both gridded products and in situ measurements which thus should be used with care in the Adriatic region for climate studies at local and regional scales. Long-term simulations with the AdriSC climate model, which couples the WRF 3-km model with a 1-km ocean model, might thus be a new avenue to substantially improve the reproduction, at the climate scale, of the Adriatic Sea dynamics driving the Eastern Mediterranean thermohaline circulation. As such it may also provide new standards for climate studies of orographically-developed coastal regions in general.

scholarly journals Reconstructions Improvements Using Iteratively Adjusted Statistics, Demonstrated Using Model-Output Annual SST Anomalies and Historical Sampling

2016 ◽  
Vol 33 (11) ◽  
pp. 2289-2303
Author(s):  
Thomas M. Smith
Keyword(s):  
Climate Models ◽  
Simulated Data ◽  
Early Years ◽  
Historical Period ◽  
Climate Variations ◽  
Base Period ◽  
Reconstruction Methods ◽  
The Tropics ◽  
Climate Studies ◽  
Sst Anomalies

AbstractHistorical reconstructions of climate fields, such as sea surface temperature (SST), are important for climate studies and monitoring. Reconstructions use statistics from a well-sampled base period to analyze a sparsely sampled historical period. Here a method is shown for adjusting the base-period statistics using the available historical data so that statistics better represent historical variations. The method is demonstrated using annual SST anomalies from a coupled GCM historical run, 1861–2005, forced by greenhouse gases and aerosols. Simulated data are constructed from the model’s SST using observed historical SST sampling with error estimates added. Reconstructions are performed using the simulated data, and the results are compared to the full model SST without added errors. The results from applying other reconstruction methods to the simulated data are compared. The tests show that the method improves annual SST reconstructions, especially in the early years, when sampling is most sparse and in the extratropics. In particular, the 1881–1900 correlation averaged over 30°–60°S and over 30°–60°N improves from about 0.4 using noniterative reconstruction to about 0.6 using iterative reconstruction. The correlations of annual values in the tropics are about 0.7 with both methods. Incorporating those improvements into an SST reconstruction could better represent extratropical climate variations in the nineteenth and early twentieth centuries, and improve the value of the reconstruction for long-period climate studies and for validating climate models.

scholarly journals On the importance of observational data properties when assessing regional climate model performance of extreme precipitation

2013 ◽  
Vol 10 (6) ◽  
pp. 7003-7043 ◽  
Author(s):  
M. A. Sunyer ◽  
H. J. D. Sørup ◽  
O. B. Christensen ◽  
H. Madsen ◽  
D. Rosbjerg ◽  
...  
Keyword(s):  
Observational Data ◽  
Spatial Correlation ◽  
Extreme Precipitation ◽  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Model Performance ◽  
Climate Model Output ◽  
Extreme Precipitation Indices ◽  
Climate Studies

Abstract. In recent years, there has been an increase in the number of climate studies addressing changes in extreme precipitation. A common step in these studies involves the assessment of the climate model performance. This is often measured by comparing climate model output with observational data. In the majority of such studies the characteristics and uncertainties of the observational data are neglected. This study addresses the influence of using different observational datasets to assess the climate model performance. Four different datasets covering Denmark using different gauge systems and comprising both networks of point measurements and gridded datasets are considered. Additionally, the influence of using different performance indices and metrics is addressed. A set of indices ranging from mean to extreme precipitation properties is calculated for all the datasets. For each of the observational datasets, the RCMs are ranked according to their performance using two different metrics. These are based on the error in representing the indices and the spatial correlation. In comparison to the mean, extreme precipitation indices are highly dependent on the spatial resolution of the observations. The spatial correlation also shows differences between the observational datasets. These differences have a clear impact on the ranking of the climate models, which is highly dependent on the observational dataset, the index and the metric used. The results highlight the need to be aware of the properties of observational data chosen in order to avoid overconfident and misleading conclusions with respect to climate model performance.

Toward dynamic global vegetation models for simulating vegetation–climate interactions and feedbacks: recent developments, limitations, and future challenges

2010 ◽  
Vol 18 (NA) ◽  
pp. 333-353 ◽  
Author(s):  
Anne Quillet ◽  
Changhui Peng ◽  
Michelle Garneau
Keyword(s):  
Land Use ◽  
Vegetation Dynamics ◽  
Climate Models ◽  
Global Climate ◽  
Evaluation Methodology ◽  
Dynamic Global Vegetation Models ◽  
Vegetation Models ◽  
Global Vegetation ◽  
Dynamics Models ◽  
Climate Studies

There is a lack in representation of biosphere–atmosphere interactions in current climate models. To fill this gap, one may introduce vegetation dynamics in surface transfer schemes or couple global climate models (GCMs) with vegetation dynamics models. As these vegetation dynamics models were not designed to be included in GCMs, how are the latest generation dynamic global vegetation models (DGVMs) suitable for use in global climate studies? This paper reviews the latest developments in DGVM modelling as well as the development of DGVM–GCM coupling in the framework of global climate studies. Limitations of DGVM and coupling are shown and the challenges of these methods are highlighted. During the last decade, DGVMs underwent major changes in the representation of physical and biogeochemical mechanisms such as photosynthesis and respiration processes as well as in the representation of regional properties of vegetation. However, several limitations such as carbon and nitrogen cycles, competition, land-use and land-use changes, and disturbances have been identified. In addition, recent advances in model coupling techniques allow the simulation of the vegetation–atmosphere interactions in GCMs with the help of DGVMs. Though DGVMs represent a good alternative to investigate vegetation–atmosphere interactions at a large scale, some weaknesses in evaluation methodology and model design need to be further investigated to improve the results.

Global temperature and hydroclimate in warmer climates of the past and future: the Last Interglacial versus greenhouse scenarios

2021 ◽  
Author(s):  
Paolo Scussolini ◽  
Pepijn Bakker ◽  
Paolo De Luca ◽  
Dim Coumou ◽  
Joyce Bosmans ◽  
...  
Keyword(s):  
Time Horizon ◽  
Climate Models ◽  
Last Interglacial ◽  
Recent Period ◽  
The Past ◽  
Temperature And Precipitation ◽  
Hemispheric Temperature ◽  
The Future ◽  
Quantitative Manner ◽  
Climate Studies

<p>Past climates contain precious information about the workings of the climate system, and about what can be expected in a changed climate. The Last Interglacial (LIG; ca. 125,000 years ago) is the most recent period of climate warmer than modern, at least in the Northern Hemisphere. Because of this, it has been often proposed that the LIG holds a partial analogy with a future warmer climate forced by enhanced greenhouse effect. Still, such analogy has never been examined in a quantitative manner. Here we address the question: for which scenario, time horizon, regions and season is the climate of the LIG a useful analogue of the future? We use the results of 13 climate models that performed the standard experiments of PMIP4 and CMIP6, and present a comparison of hemispheric temperature and precipitation between the LIG and SSP scenarios of the future. We also two independent assessments of models performance, by comparing their temperature and precipitation to climate reanalysis of the last decades and to proxies of the LIG. Insights gained from this comparison can inform studies in disciplines beyond climate studies, such as hydrology and ecology.</p>

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