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### Messages - Sonali

Pages: 1 ... 20 21 [22] 23
316
##### Programming / Re: Trend analysis using Robust Methods
« on: January 07, 2013, 01:48:51 PM »
I too found some 's' values negative and some 's' values positive.

317
##### Programming / Re: Trend analysis using Robust Methods
« on: January 07, 2013, 12:45:24 PM »
Hi,

I have gone through all the discussion.
Like Sat Kumar I too found your code is perfectly fine.
I tested  your code in Matlab. It is giving correct result.

I have already applied sen's slope to find out  trend magnitude in annual maximum temperature of (EC) East Coast region (temperature homogeneous region defiened by IMD) for the period 1901-2003.

Validated result is mentioned in the following link

http://www.sciencedirect.com/science/article/pii/S0022169412009341

To validate your code I applied the same to find out trend and I got the same result (keeping dt=1).
Result from your code is matching with the result mentioned in the given article. [page-220; Table-2]
trend magnitude=0.0023

Mann-Kendall Test:
n           = 103
Mean Value  = 36.5718
Z statistic = 0.9717
No significant trend
Sen's Nonparametric Estimator:
Slope Estimate = 0.0022727
Lower Confidence Limit = -0.0022989
Upper Confidence Limit = 0.0076923

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Result from the code used in the mentioned article:-
b=0.0022727~0.0023;

Regards,

Sonali

318
##### Data / Re: CMIP5 Data
« on: October 26, 2012, 11:15:35 AM »
of course it will be good and helpful for all of us.

319
##### Data / Re: CMIP5 Data
« on: October 23, 2012, 02:11:16 PM »
Its true. Satkumar is correct...

320
##### Models / Re: Image classification using Active Microwave Remote Sensing
« on: October 22, 2012, 01:11:24 PM »
Sorry for the late response but

That presentation was interesting I too heard it,  even though I do not understand much about this subject, he explained nicely.

321
##### Models / Re: Image classification using Active Microwave Remote Sensing
« on: October 22, 2012, 01:01:48 PM »
That presentation was interesting I too heard it,  even though I do not understand much about this subject, he explained nicely.

322
##### Data / Re: Regarding GCM data
« on: October 22, 2012, 12:40:55 PM »
I have pre-industrial control run data for near surface temperature from PCM1, cccma_cgcm3_1_t63, CCSM3 from CMIP3 and CCSM4 from CMIP5. I have also natural runs data from PCM1.
In the following web site you can get the information about all the data.

https://esg.llnl.gov:8443/index.jsp

Downloading data via FTP may provide faster speed for all the data set which is really lengthy such as GCM outputs from control run.

https://esg.llnl.gov:8443/index.jsp

323
##### Data / Re: CMIP5 Data
« on: October 22, 2012, 12:21:06 PM »
All the details what you have explained Ujjwal are really very helpful. The documents attached are also very nice and easy to understand. Thanks a lot. It will be really useful for all of those, who are going to work in CMIP5 data set. As there is lot of difference between the name of all scenarios in CMIP3 and CMIP5, these documents will give a clear picture to the to the entire CMIP5 data users. In the beginning it takes really a lot of time to find all this information. Your inputs towards CMIP5 data set handing is very useful and could be helpful in saving lots of time.

Once again thanks a lot Ujjwal....Really a very good job....

324
##### Data / Re: Regarding GCM data
« on: October 22, 2012, 12:06:35 PM »
I have NCEP Reanalysis Data from 5 to 45 North 65 to 95 East for air temperature at 2 meter, skin temperature, maximum & minimum  temperature, air temperature at 200hpa, 500 hpa and 850hpa respectively.  The NCEP/NCAR Reanalysis outputs for all the variables are available in the following web site:
http://www.esrl.noaa.gov/psd/data/reanalysis/reanalysis.shtml
Again for the same variables I have data from GCM BCCR_BCCM2_0, GISS  AOM, IPSL CM4, MIROC3.2 medres, MRI-CGCM2, NCAR-PCM1 and UKMO-hadcm3 models and some more data set from some other variables. All these data sets are the outputs of the models participated IPCC AR4 for 20C3M scenario. AR4 GCM data for all the variables and for all the scenarios are available in the following web site:

325
##### Post your question/information / Re: Very Interesting How numerals 0 – 9 got their shape
« on: September 22, 2012, 08:52:30 AM »
Thanks Ujjwal..

326
##### Post your question/information / Very Interesting How numerals 0 – 9 got their shape
« on: September 21, 2012, 07:23:07 PM »
Click the following link to know How numerals 0 – 9 got their shape...

327
##### Models / Re: Bias correction methods
« on: September 21, 2012, 03:12:37 PM »
Good reference for bias correction.

http://www.agu.org/pubs/crossref/2012/2011WR010464.shtml

WATER RESOURCES RESEARCH, VOL. 48, W01504, 16 PP., 2012
doi:10.1029/2011WR010464

A nesting model for bias correction of variability at multiple time scales in general circulation model precipitation simulations

328
##### Models / Re: Bias correction methods
« on: September 21, 2012, 02:57:40 PM »
Short note on types of bias correction, regarding which Sat Kumar has explained above.

Some points which I had collected during my initial literature review.

Event Bias Correction Method: Proposed by Smith et al.(1992), assumes that for a given historical weather sequence, the same multiplicative bias exists each time the sequence is used to simulate an ensemble trace, regardless of the initial conditions.

Regression Method: The regression method removes bias by replacing the simulated value with the expected value of the observed data, given the simulated value.

Quantile Mapping Method: The quantile mapping method uses the empirical probability distributions for observed and simulated values to remove biases. Mainly used for bias correction of atmospheric models (Wood et al. 2004)

Statistical Bias Correction Method: Proposed by Piani et al.(2008) It is based on the initial assumption that both observed and simulated intensity distributions are well approximated by some pre defined (for e.g. Gamma Distribution) distribution.

329
##### Interesting information / Re: How to Prepare for the Comprehensive Exam?
« on: September 21, 2012, 02:15:29 PM »
Nice article. I feel all the points explained in this article are, genuinely true.

330
##### Programming / Re: Selection of ROI
« on: August 14, 2012, 01:06:28 PM »
Very good Sat Kumar you have solution for everything....You are really  great......

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