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
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Note the return stokes and bolts...!!
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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

http://keelingcurve.ucsd.edu/

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.....

http://earthobservatory.nasa.gov/Features/ColorImage/?src=eorss-features

fulldiskwest_goe_2013257_crop_720
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
http://climate.nasa.gov/scientific-consensus

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

Wednesday, January 30, 2013

Global warming and Precipitation

Global warming from greenhouse gases affects rainfall patterns in the world differently than that from solar heating, according to a study.
The scientists, led by Jian Liu (Chinese Academy of Sciences) and Bin Wang (International Pacific Research Center, University of Hawaii at Manoa), showed that global rainfall has increased less over the present-day warming period than during the Medieval Warm Period, even though temperatures are higher today than they were then.
As a result of global warming, precipitation is likely to increase in high latitudes and the tropics and to decrease in already dry subtropical regions.

Read More
http://phys.org/news/2013-01-greenhouse-gases-solar-complexity-global.html
http://www.nature.com/nature/journal/v493/n7434/full/nature11784.html

doi:10.1038/nature11784

Thursday, January 17, 2013

Global Warming Trends ... alarming

Long-Term Global Warming Trend Continues

2012 was the ninth warmest year since 1880.
The map at the top depicts temperature anomalies, or changes, by region in 2012; it does not show absolute temperature. Reds and blues show how much warmer or cooler each area was in 2012 compared to an averaged base period from 1951–1980. For more explanation of how the analysis works, read World of Change: Global Temperatures.

The average temperature in 2012 was about 14.6 degrees Celsius (58.3 degrees Fahrenheit), which is 0.55°C (1.0°F) warmer than the mid-20th century base period. The average global temperature has increased 0.8°C (1.4°F) since 1880, and most of that change has occurred in the past four decades.

Read more: http://earthobservatory.nasa.gov/IOTD/view.php?id=80167&src=eoa-iotd