Tuesday, October 17, 2017

Cloud feedback regulating the “pool of inhibited cloudiness”

Our latest paper on the"Role of cloud feedback in regulating the “pool of inhibited cloudiness” over the Bay of Bengal"
published in Springer Nature's  Meteorology and Atmospheric Physics.

Read & Share Full Article here:

Anish Kumar M. Nair,  T. N. Rao and  K. Rajeev 

 Reference .bib

  author   = {Nair, Anish Kumar M. and Rao, T. Narayana and Rajeev, K.},
  title    = {Role of cloud feedback in regulating the “pool of inhibited cloudiness” over the Bay of Bengal},
  journal  = {Meteorology and Atmospheric Physics},
  year     = {2017},
  pages    = {1--12},
  month    = {10},
  issn     = {0177-7971},
  abstract = {Cloud-circulation feedback by latent heating (LH) is a major contributor for driving atmospheric circulation. This study examines the potential role of spatial variations of LH in driving a mini-circulation for generating the “pool of inhibited cloudiness”, where cloud formation in the lower and middle troposphere is significantly inhibited over the southwest Bay of Bengal (BoB) during the Indian summer monsoon. Spaceborne observations show that LH rates in the deep convective regions of the head BoB are as high as 0.2 K/h, while that over the “pool” are about 5 times smaller. This differential heating results in modulating the mean circulation. 20 years of reanalysis data show good correlation between (a) upper troposphere (300 hPa) convergence and lower tropospheric (1000 hPa) divergence at the “pool” and (b) lower tropospheric divergence at the “pool” and lower tropospheric convergence at the head BoB as well as at the west coast of India. Besides the orographic influence, a portion of the air mass descending at the “pool” arises from deep convective regions in the north BoB and equatorial trough. This subsidence is responsible for the persistent inhibition to cloud formation at the “pool”. This case forms a classic example of the cloud-circulation feedback.},
  doi      = {10.1007/s00703-017-0560-7},
  url      = {http:https://doi.org/10.1007/s00703-017-0560-7},


Wednesday, October 11, 2017

TV interview with Dr.Suresh Babu, Scientist, SPL, VSSC, ISRO

Congrats Dr. Suresh Babu for bagging the prestigious Shanthi Swarup Bhatnagar Prize 2017.

Proud of you...!!!
Wishing you and team more success !!

Friday, September 23, 2016

Autumnal Equinox 2016 as seen from Space (animated)

An Equinox is the astronomical event when both the hemispheres have equal duration and amount of sunshine.
Sun would be exactly overhead of the equator.
It happens twice in a year Spring (Summer) equinox (20 March) and Vernal (Autumnal) equinox (22 September).

Here is the view of the beautiful event from space for 22 September 2016.
I have animated it (time series for the day).
Watch the day-night solar terminator move through the earth.
Observe the equal area of sunshine and night on either hemisphere.

The visible imagery is from MeteoSat VISSR (IODC) stationed at 57deg.E longitude above equator in a geostationary orbit.

For a typical comparison of Equinoxes with Solistices, you may go through this link http://akmnscience.blogspot.in/2012/07/equinox-solstice-better-view.html

Image Courtesy: Dundee Satellite Receiving Station http://www.sat.dundee.ac.uk/

Tuesday, March 8, 2016

Solar Eclipse over Tirupati 09 Mar 2016 (simulated)

Solar Eclipse (09 Mar 2016) is hardly visible over Tirupati.

Here is an animated version (Figure (a)) of the simulation I have prepared using the free open source "Stellarium" software.

The Sun rises over Tirupati by 06:23 IST.
Meanwhile eclipse has already begun and being in penumbra region, it's partial eclipse over here.

For reference, the figure (b) of eclipse locations are shown in the figure below (scroll down) which also shows time in Tirupati during the events. 
(courtesy: timeanddate.com )

Figure (a): Animation of the solar eclipse (simulated) over Tirupati.
'E' indicates East

Figure (b): How eclipse happens world wide (courtesy: timeanddate.com)

Wednesday, June 10, 2015

Lightning Photography

I am sharing a few photos of Lightning I had clicked yesterday night over National Atmospheric Research Laboratory, Dept. of Space located at Gadanki, Andhra Pradesh, India.

Cumulonimbus cloud band was observed in the eastern and southern sky and Gadanki was in periphery of the rain band.

Also see the animated time series photos of the steps of lightning
Note the return stokes and bolts...!!
Recommended viewing: Full screen.Thanks to my Asus Zenfone.

Wednesday, May 7, 2014

CO2 at Record High concentration

Concentrations of the greenhouse gas carbon dioxide (CO2) in the global atmosphere has surpassed 400 ppm  for the first time in human history in April.
As on May 03, 2014 the value is still higher 401.80 ppm.

Read more from official website


Here is the screen shot.
Courtesy: Scripps Institute of Oceanography

Tuesday, November 19, 2013

Satellite Images - Easy to interpret

Satellite images are are rich with useful and interesting information.
It is not difficult to interpret them...
here are some tips and stratergies....

 High-resolution satellite view of the Boulder water treatment plant.

 They can show us how much a city has changed, how well our crops are growing, where a fire is burning, or when a storm is coming.

 Here is a practical approach as given by Nasa Earth Observatory.

  1. Look for a scale
  2. Look for patterns, shapes, and textures
  3. Define the colors (including shadows)
  4. Find north
  5. Consider your prior knowledge
Read more....
Check this link.....


Courtesy: Nasa Earth Observatory

Thursday, October 31, 2013

Antarctic Sea Ice Growing ?

Every year during winter time (Aug-Sep) , extend of Antarctic sea ice  increases.
But this year...... it has reached record largest extend....
Reports NASA.
Interesting .....!  Isn't it....?
Antarctic Sea Ice Reaches New Maximum Extent

Read the following graph to compare the changes in sea ice extend.

Read More:
Antarctic Sea Ice Reaches New Maximum Extent

Why should it grow....?
It's an interesting field of research....!

There are few hypothesis...
Read More http://theconversation.com/why-is-antarctic-sea-ice-growing-19605

 Courtesy: NASA earth observatory

Monday, July 29, 2013

Warmest Decade

Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record.
Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record.

Courtesy:Nasa Global CLimate change

Friday, July 12, 2013

El Nino activity in 2oth century and global warming

High El Nino -Southern Oscillation (ENSO) activity in the late 20th century is a footprint of global warming says a recent study.
An international team of scientists spearheaded by Jinbao Li and Shang-Ping Xie, while working at the International Pacific Research Center, University of Hawaii at Manoa, has compiled 2,222 tree-ring chronologies of the past seven centuries from both the tropics and mid-latitudes in both hemispheres. Their work is published in the June 30, 2013 online issue of Nature Climate Change.

Li, J., S.-P. Xie, E. R. Cook, M. Morales, D. Christie, N. Johnson, F. Chen, R. D'Arrigo, A. Fowler, X. Gou, and K. Fang (2013): El Niño modulations over the past seven centuries. Nature Climate Change. http://dx.doi.org/10.1038/nclimate1936

Caption: This graph shows El Niño variability derived from tree rings (blue) and instrumental measurements (red). The dashed lines indicate boundary for natural variability. Recent El Niño behavior is largely beyond natural variability.
Credit: International Pacific Research Center

Read More: http://www.eurekalert.org/pub_releases/2013-06/uoha-enu062813.php
and http://dx.doi.org/10.1038/nclimate1936