This meteorology image could be re-created using vector graphics as an SVG file. This has several advantages; see Commons:Media for cleanup for more information. If an SVG form of this image is available, please upload it and afterwards replace this template with {{vector version available|new image name}}. It is recommended to name the SVG file “Annual Average Temperature Map.svg”—then the template Vector version available (or Vva) does not need the new image name parameter.

This meteorology image was uploaded in the JPEG format even though it consists of non-photographic data. This information could be stored more efficiently or accurately in the PNG or SVG format. If possible, please upload a PNG or SVG version of this image without compression artifacts, derived from a non-JPEG source (or with existing artifacts removed). After doing so, please tag the JPEG version with {{Superseded|NewImage.ext}} and remove this tag. This tag should not be applied to photographs or scans. If this image is a diagram or other image suitable for vectorisation, please tag this image with {{Convert to SVG}} instead of {{BadJPEG}}. If not suitable for vectorisation, use {{Convert to PNG}}. For more information, see {{BadJPEG}}.

خلاصہ

This is a global map of the annually averaged near-surface air temperature from 1961 to 1990. Such maps, also known as "climatologies", provide information on climate variation as a function of location.

The tropics, between the Tropic of Cancer and Tropic of Capricorn, have the most direct sunlight and highest temperatures. While the seasonal contrasts in surface temperature are due to the tilt of the Earth axis, there is relatively little variation in the annual average sunlight received throughout this entire tropics, and hence the entire band has similar temperatures. Above the tropics, temperatures fall off more rapidly as one travels towards the Earth's poles, at a rate of approximately 1 °C for every 145 km (1 °F per 50 miles). Permafrost will form at positions where the annual average temperature is below 0 °C.

The other key factor in determining surface temperature is elevation. Surface temperature declines ~1 °C for every 220 m (1 °F per 400 ft) in elevation above sea level. The coldest portions of Earth are the Greenland and Antarctic Ice Sheets, which combine both very high latitude and high elevation.

Data sources

This map was produced by combining the 10' CRU CL 2.0 archive copy at the Wayback Machine land-surface temperature data set (New et al. 2002) with the 1° NOAA OISST version 2 archive copy at the Wayback Machine sea-surface temperature data set (Reynolds et al. 2002) and the 2.5° NCEP/NCAR Reanalysis version 1 archive copy at the Wayback Machine data set (Kalnay et al. 1996). OISST was used for low- and mid-latitude ocean temperatures, but NCEP/NCAR was substituted in sea ice-forming regions, where OISST would overestimate the near-surface air temperature. In addition, a small offset was added in all regions to the OISST sea-surface temperatures to match the NCEP/NCAR air temperatures, and thus account for the difference between ocean and air. NCEP/NCAR was used for Antarctica, since it was the only data set including this region.

Copyright

This image was created by Robert A. Rohde for Global Warming Art.

Image from Global Warming Art

This image is an original work created for Global Warming Art. Please refer to the image description page for more information.

آپ کو آزاد سافٹ ویئر فاؤنڈیشن کی جانب سے شائع کردہ جی این یو آزاد مسوداتی اجازت نامہ کی شرائط استعمال کے تحت اس دستاویز کو نقل، تقسیم اور/ یا ترمیم کرنے کی اجازت دی جاتی ہے۔ اس اجازت نامہ کی ایک نقل 'جی این یو آزاد مسوداتی اجازت نامہ کے عنوان سے میسر ہے۔http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue

	اس ملف کا لائسنس Creative Commons Attribution-Share Alike 3.0 Unported کے تحط ہے۔
	آپ آزاد ہیں: شیئر کرنے – کام کو نقل، تقسیم یا منتقل کرنے کے لیے ریمکس کے لیے – کام منبطق کرنے کے لیے مندرجہ ذیل شرائط کے تحت: انتساب – آپ کو اس کام کا انتساب مصنف یا اجازت دہندہ کے بتائے گئے طریقہ کے مطابق دینا ہوگا (تاہم یہ انتساب اس طرح نہیں ہونا چاہیے کہ اسے دیکھ کر ایسا محسوس ہو کہ اصل مصنف یا اجازت دہندہ آپ کے یا آپ کے ذریعہ اس کام کے استعمال کرنے کے حامی ہیں)۔ یکساں شراکت – اگر آپ اس کام میں کوئی تبدیلی یا ترمیم کرتے ہیں یا اس کام پر مبنی کچھ نیا بناتے ہیں تو اسے بھی آپ اسی یا اس جیسے کسی اجازت نامے کے تحت شائع کر سکتے ہیں۔
	This licensing tag was added to this file as part of the GFDL licensing update.http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue

Une deuxième raison pour laquelle la température de surface dépend de la latitude est la variation de l’épaisseur d'atmosphère traversée par les rayons lumineux. Lorsque les rayons sont perpendiculaires à la surface, l'épaisseur d'atmosphère traversée est la plus faible ; la lumière est moins absorbée et moins diffusée par l’atmosphère et la surface reçoit d'avantage d'énergie solaire. A l’équateur la surface du globe est, côté soleil, perpendiculaire au rayonnement solaire tandis que près des pôles la surface est presque parallèle. L’énergie solaire reçue par unité de surface est donc plus importante près de l’équateur que près des pôles.

References

• New, Mark, David Lister, Mike Hulme, Ian Makin (2000). "A high-resolution data set of surface climate over global land areas". Climate Research 21: 1-25. Archived from the original on 2009-02-12. Retrieved on 2008-02-15.
• Reynolds, R.W., N.A. Rayner, T.M. Smith, D.C. Stokes, and W. Wang (2002). "An improved in situ and satellite SST analysis for climate". J. Climate 15: 1609-1625.
• E. Kalnay, M. Kanamitsu, R. Kistler, W. Collins, D. Deaven, L. Gandin, M. Iredell, S. Saha, G. White, J. Woollen, Y. Zhu, M. Chelliah, W. Ebisuzaki, W.Higgins, J. Janowiak, K. C. Mo, C. Ropelewski, J. Wang, A. Leetmaa, R. Reynolds, Roy Jenne, Dennis Joseph (1996). "The NCEP/NCAR 40-Year Reanalysis Project". Bulletin of the American Meteorological Society 77 (3): 437–471.

derivative works

Derivative works of this file:  Annual Average Temperature Map East Asia.png