Predictability in limited area and global models

Paegle, Jan; Yang, Qiang; Wang, Muyin

doi:10.1007/bf01025364

Cited by 33 publications

(26 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result is in contrast to the result of other authors (see, e.g., a survey in Paegle et al 1997). We conclude that the weaker large-scale boundary forcing in our ARC domain discussed in Section 3 leads to the stronger sensitivity.…”

Section: Influence Of the Initial State On The Simulationcontrasting

confidence: 56%

“…Due to the weaker lateral boundary control a more pronounced sensitivity to uncertainties in initial conditions is found in comparison to other mesoscale models, as discussed, e.g., in Paegle et al (1997). The uncertainty in the initial conditions, which in Arctic regions as a result of coarse data is especially large, sets an upper limit for improvements of the bias of any RCM.…”

Section: Discussionmentioning

confidence: 89%

See 1 more Smart Citation

On the sensitivity of a regional Arctic climate model to initial and boundary conditions

Rinke¹,

Dethloff²

2000

Clim. Res.

View full text Add to dashboard Cite

The sensitivity of Arctic atmospheric simulations to initial and boundary conditions was investigated with the high horizontal resolution regional climate model HIRHAM driven by observational data analyses at the lateral and lower boundaries. Investigation of the constraint of the synopticscale flow in the specific circumpolar Arctic domain showed that even though the same domain size as in mid-latitude RCM (regional climate model) simulations was used, a weaker constraint of the synoptic scales and a smaller predictability were obtained. A simple spectral analysis showed that only scales with wavelengths longer than 1000 km contribute to the higher root-mean-square difference. Due to the weaker lateral boundary control a pronounced sensitivity of the Arctic simulations to uncertainties in initial conditions was found. The changes in the monthly mean atmospheric structures due to internal processes were of the same order as those due to inaccurate physical parameterizations. Sensitivity experiments concerning changed sea ice thickness showed a substantial impact of the lower boundary conditions on the monthly mean atmospheric structures up to the middle troposphere.KEY WORDS: Regional climate model evaluation · Initial and boundary conditions · HIRHAM · Arctic climate Clim

show abstract

Section: Influence Of the Initial State On The Simulationcontrasting

confidence: 56%

Section: Discussionmentioning

confidence: 89%

On the sensitivity of a regional Arctic climate model to initial and boundary conditions

Rinke¹,

Dethloff²

2000

Clim. Res.

View full text Add to dashboard Cite

show abstract

“…Error growth in limited-area models is strongly limited by the imposed model boundary conditions (Anthes et al 1985;Paegle et al 1997). Simulations from limited-area models can reproduce well many of the observed features if the boundary conditions are good but cannot overcome errors in the global data that drive the boundary conditions (Mo et al 2005).…”

Section: Mesoscale Model Descriptionmentioning

confidence: 98%

Impact of Tropical Easterly Waves on the North American Monsoon

Adams

Stensrud

2007

Journal of Climate

View full text Add to dashboard Cite

The North American monsoon (NAM) is a prominent summertime feature over northwestern Mexico and the southwestern United States. It is characterized by a distinct shift in midlevel winds from westerly to easterly as well as a sharp, marked increase in rainfall. This maximum in rainfall accounts for 60%-80% of the annual precipitation in northwestern Mexico and nearly 40% of the yearly rainfall over the southwestern United States. Gulf surges, or coastally trapped disturbances that occur over the Gulf of California, are important mechanisms in supplying the necessary moisture for the monsoon and are hypothesized in previous studies to be initiated by the passage of a tropical easterly wave (TEW). Since the actual number of TEWs varies from year to year, it is possible that TEWs are responsible for producing some of the interannual variability in the moisture flux and rainfall seen in the NAM.To explore the impact of TEWs on the NAM, four 1-month periods are chosen for study that represent a reasonable variability in TEW activity. Two continuous month-long simulations are produced for each of the selected months using the Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model. One simulation is a control run that uses the complete boundary condition data, whereas a harmonic analysis is used to remove TEWs with periods of approximately 3.5 to 7.5 days from the model boundary conditions in the second simulation. These simulations with and without TEWs in the boundary conditions are compared to determine the impact of the waves on the NAM. Fields such as meridional moisture flux, rainfall totals, and surge occurrences are examined to define similarities and differences between the model runs. Results suggest that the removal of TEWs not only reduces the strength of gulf surges, but also rearranges rainfall over the monsoon region. Results further suggest that TEWs influence rainfall over the Southern Plains of the United States, with TEWs leading to less rainfall in this region. While these results are only suggestive, since rainfall is the most difficult model forecast parameter, it may be that TEWs alone can explain part of the inverse relationship between NAM and Southern Plains rainfall.

show abstract

“…Vukicevic and Errico 1990; Peagle et al 1997;Laprise et al 2000;de Elı´a et al 2002), predictability in nested limited-area models (LAM) is different from global models. Errors in the initial conditions do not grow beyond an asymptotic value that is much smaller than the value expected for a total loss of predictability as in a global model.…”

Section: Discussionmentioning

confidence: 99%

Testing the downscaling ability of a one-way nested regional climate model in regions of complex topography

Antic

Laprise

Denis³

et al. 2005

Clim Dyn

View full text Add to dashboard Cite

The downscaling ability of a one-way nested regional climate model (RCM) is evaluated over a region subjected to strong surface forcing: the west of North America. The sensitivity of the results to the horizontal resolution jump and updating frequency of the lateral boundary conditions are also evaluated. In order to accomplish this, a perfect-model approach nicknamed the Big-Brother Experiment (BBE) was followed. The experimental protocol consists of first establishing a virtual-reality reference climate over a fairly large area by using the Canadian RCM with grid spacing of 45 km nested within NCEP analyses. The resolution of the simulated climate is then degraded to resemble that of operational general circulation models (GCM) or observation analyses by removing small scales; the filtered fields are then used to drive the same regional model, but over a smaller sub-area. This set-up permits a comparison between two simulations of the same RCM over a common region. The Big-Brother Experiment has been carried out for four winter months over the west coast of North America. The results show that complex topography and coastline have a strong positive impact on the downscaling ability of the one-way nesting technique. These surface forcings, found to be responsible for a large part of small-scale climate features, act primarily locally and yield good climate reproducibility. Precipitation over the Rocky Mountains region is a field in which such effect is found and for which the nesting technique displays significant downscaling ability. The best downscaling ability is obtained when the ratio of spatial resolution between the nested model and the nesting fields is less than 12, and when the update frequency is more than twice a day. Decreasing the spatial resolution jump from a ratio of 12 to six has more benefits on the climate reproducibility than a reduction of spatial resolution jump from two to one. Also, it is found that an update frequency of four times a day leads to a better downscaling than twice a day when a ratio of spatial resolution of one is used. On the other hand, no improvement was found by using high-temporal resolution when the driving fields were degraded in terms of spatial resolution.

show abstract

Predictability in limited area and global models

Cited by 33 publications

References 28 publications

On the sensitivity of a regional Arctic climate model to initial and boundary conditions

On the sensitivity of a regional Arctic climate model to initial and boundary conditions

Impact of Tropical Easterly Waves on the North American Monsoon

Testing the downscaling ability of a one-way nested regional climate model in regions of complex topography

Contact Info

Product

Resources

About