climate and time scales how do time scales affect the spatial extent of a climate signal?
DESCRIPTION
Climate and Time Scales How do time scales affect the spatial extent of a climate signal?. Angela Colbert, Jie He, Johnna Infanti, Hosmey Lopez April 27, 2011. Data. CCSM3 Model Ocean variables (10 to choose from) have a 1 x 1 degree resolution horizontally and 40 vertical levels. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/1.jpg)
Climate and Time ScalesHow do time scales affect the spatial extent of a climate signal?
Angela Colbert, Jie He, Johnna Infanti, Hosmey LopezApril 27, 2011
![Page 2: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/2.jpg)
DataCCSM3 Model
Ocean variables (10 to choose from) have a 1 x 1 degree resolution horizontally and 40 vertical levels.
Atmospheric variables (many to choose from) have a T42 spectral (wavenumber 42 truncation) or about 2.8 degree resolution horizontally and 8 vertical levels.
The time resolution is monthly with a total time record from January 0710 to December 1543 (model years)
![Page 3: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/3.jpg)
General MethodologyIdentify important time scales for analysis
Subseasonal, seasonal, annual, and decadalCompute EOFs based on time scales and regions of
interestEOF analysis use a 3D dataset, thus obtain a spatial pattern
EOF (2D) and PC (time series)Interpret the resulting spatial patterns
What is the spatial extent? Can you find the various known climate signals?
PDO, ENSO, etc. How does that compare with other time scales?
![Page 4: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/4.jpg)
Sub-seasonal time scale forcing on large scalesThe main goal here is to study the impact of sub-seasonal and
synoptic scales in the large scales tropical ocean-atmosphere.
Here, we will analyze Westerly Wind Bursts (WWB) events that occurs on the western Pacific at about the equator and its interaction with the large scale Sea Surface Temperature (SST).
This WWB were introduced in CCSM3 as semi-stochastic forcing, modulated by the SST. Here the bursts have an stochastic (random) component. Its dependence on the large scale SST is calculated based on reanalysis wind data
and observational estimates of SST
![Page 5: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/5.jpg)
The analysis method:
![Page 6: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/6.jpg)
![Page 7: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/7.jpg)
![Page 8: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/8.jpg)
Lag-lead correlation of SST along the equator and WWB parameters
![Page 9: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/9.jpg)
![Page 10: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/10.jpg)
1 2 3 4 5 6 7
Amplitude 43 2 -35 15 -61 53 0
Central Lon. 12 -99 -2 9 -6 2 0
East extent 42 -10 10 -40 19 7 -77
West extent -28 -4 79 10 13 43 28
Zonal extent -44 -12 -26 -59 20 -12 57
Persistence -34 -1 -34 60 64 8 0
Probability -49 -3 23 30 -33 71 0
Covariance % 59 33 4.3 1.3 0.9 0.5 0
WWB Variance %
64 13 9 5 4 5 0
Modes of WWB matrix
• 1st EOF is dominated by the probability, zonal and eastern extents, and amplitude. This mode represent ENSO and accounts for 64% of the burst variance.
• 2nd EOF is dominated by the central longitude and accounts for 33% of WWB variance. This mode reflect the seasonal cycle.
• 3rd EOF, mostly dominated by the western extent, amplitude, and persistence. It accounts for only 9% of WWB variance. This mode rensemble equatorial wave activity.
• 4th EOF is dominated by the persistence and zonal extent. 5% of burst variance is explained here. This mode reflects a zonal dipole in SST, but only 1.3% of the covariance is explained.
![Page 11: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/11.jpg)
Seasonal SST (Skin Temperature) Results
![Page 12: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/12.jpg)
Seasonal SST (Skin Temperature) Results
![Page 13: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/13.jpg)
Seasonal SLP Results
![Page 14: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/14.jpg)
Seasonal SLP Results
![Page 15: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/15.jpg)
Annual SLP Results
EOF 1 – 23.73% EOF 2 – 21.65%
![Page 16: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/16.jpg)
Annual SST Results
EOF 1 – 13.57% EOF 2 – 10.09%
![Page 17: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/17.jpg)
Annual SST Results
EOF 3 – 7.09% EOF 4 – 6.06%
![Page 18: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/18.jpg)
Annual SST Results
![Page 19: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/19.jpg)
Annual SST Results - Subsection
EOF 1 – 27.81% EOF 2 – 12.23%
![Page 20: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/20.jpg)
Decadal Climate VariabilityData:250 years decadal mean sst, slp and wind stress data from CCSM3.
![Page 21: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/21.jpg)
Decadal Climate Variability over the North Pacific
![Page 22: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/22.jpg)
A Possible Mechanism for PDO
SST-SLP-Wind Feedback
SST warmer on the East;
West to East pressure gradient
Intensified Westerlies
Increased Latent Heat loss
![Page 23: Climate and Time Scales How do time scales affect the spatial extent of a climate signal?](https://reader035.vdocuments.net/reader035/viewer/2022062323/56816499550346895dd672a0/html5/thumbnails/23.jpg)
Decadal Climate Variability over the Tropical Atlantic