Reason : Why Climatology beings from 1979 onwards

Reasons behind climatology beings from 1979 onwards,

Most of the global region observation relying on satellite measurements data.

1) Satellite measurements of ice areas began in 1979

Notz Dirk, Marotzke Jochem, 2012, Observations reveal external driver
for Arctic sea-ice retreat, Geophysical Research Letters, VOL. 39, L08502, doi:10.1029/2012GL051094 Link

The above paper says,

2) The pre-1953 data is pretty useless, much of it is obviously not

changing from year to year. The variation in the Hadley Centre’s Sea Ice and Sea Surface (HadISST) Temperature dataset changes pretty radically at 1979 onwards.

3) From 1979 onwards the HadISST data set is primarily based on

satellite observations. We find across the 1978/1979 boundary an
unusually large increase in sea-ice extent in March and an unusually
large decrease in sea-ice extent in September.

Source : http://wattsupwiththat.com/2012/05/03/icy-arctic-variations-in-variability/

In above link you can see the plots which shows observation variability rapid cut-off at 1979 onwards.

4) P. Nabat et al., 2013, A 4-D climatology (1979–2009) of the monthly tropospheric aerosol optical depth distribution over the Mediterranean region from a comparative evaluation and blending of remote sensing and model products, Atmos. Meas. Tech., 6, 1287-1314, doi:10.5194/amt-6-1287-2013 Link

The above paper says,

They extend the 2003–2009 reconstruction to the past up to 1979 using the 2003–2009 average and applying the decreasing trend in sulfate aerosols from LMDz-OR-INCA. Finally optical properties of the different aerosol types in this region are proposed from Mie calculations so that this reconstruction can be included in regional climate models for aerosol radiative forcing and aerosol-climate studies.

i.e. Upto 1979 observed / satellite data are reconstructed using after 1979th year observed dataset.

 

Advertisements

About arulalant

Currently working as "Project Scientist – C" in National Centre for Medium Range Weather Forecasting (NCMRWF), MoES, Noida, India
This entry was posted in Climate and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s