Heat is produced when insolation interacts with the atmosphere and the earth’s surface, and it is quantified in terms of temperature. Temperature is a measurement of how hot (or cold) something (or a place) is in degrees. Temperature is a measurement of how hot (or cold) something (or a place) is in degrees.
What is an isotherm?
The terms ‘iso’ and ‘therm’ make up an isotherm. “Iso” stands for “equal,” while “therm” stands for “temperature.” Isotherms are temperature equal line linking locations.
- The horizontal distribution of temperature appears uneven while viewing at an isotherm map.
- Net solar insolation is highest over lower latitudes and lower in higher latitudes.
- Thus, the equatorial region is hot in general, and the temperature remains high throughout the year.
- The temperature generally decreases from the equator to the poles.
- At and around the poles, the temperatures are the lowest.
- Because the seasonal extremes of high and low temperature are most visible in both the northern and southern hemispheres during these months, the horizontal distribution of temperature around the globe may be easily analysed from maps of the months of January and July.
Distribution of temperature varies both horizontally and vertically
A) Horizontal Distribution of Temperature
B) Vertical Distribution of Temperature
- The temperature distribution for January and July can be used to understand the global distribution of temperature.
- Isotherms are commonly used to depict temperature dispersion on a map. Isotherms are lines that connect points of equal temperature.
- The effects of latitude are often well represented on the map, as isotherms are generally parallel to latitudes.
- The departure from the trend is more common in January than in July, particularly in the northern hemisphere.
- The land surface in the northern hemisphere is substantially larger than in the southern hemisphere. As a result, the influence of land masses and ocean currents can be seen clearly.
Horizontal Temperature Distribution in January Month
- The sun shines vertically overhead near the tropic of Capricorn in January. As a result, summer is in the southern hemisphere and winter is in the northern.
- The southern hemisphere’s landmasses, primarily in three regions, have a high temperature. North-western Argentina, East and Central Africa, and Central Australia are the three regions in question.
- They are sealed with a 30°C isotherm.
- In a small area of the Western Australian desert, the maximum mean temperature in January is around 32 °C.
- At both 80° N and 50° N latitudes, the average January temperature along 60° E longitude is negative 20° C.
- January’s average monthly temperature is over 27° C in the tropics, over 24° C in the equatorial oceans, 2° C – 0° C in the intermediate latitudes, and –18° C to –48° C in the Eurasian continental interior.
- Landmasses in the northern hemisphere are cooler than oceans.
- The isotherms bend towards the north (poles) when they cross the oceans and to the south (equator) when they traverse the continents because the air is warmer over the oceans than over landmasses in the northern hemisphere.
- Over the North Atlantic Oceans, this can be seen plainly. Warm ocean currents (the Gulf Stream and North Atlantic Drift) warm the Northern Atlantic Ocean, causing isotherms to bend towards the poles.
- In Europe, the temperature drops dramatically across land, and the isotherms bend towards the equator.
- The oceans have a strong influence in the southern hemisphere (due to few landmasses).
Following are the Factors Accountable for the Uneven Horizontal Distribution of Temperature is:
- Land And Sea Contrast
- Ocean Currents
- Passage of Air Masses
- Vegetation Cover
Vertical Distribution of Temperature
- We’ve already shown that as height rises, the temperature in the troposphere falls.
- The standard atmosphere, also known as the Normal Lapse Rate, is a vertical temperature gradient.
- This normal lapse rate, however, varies depending on height, season, latitude, and other factors.
- The true lapse rate of temperature does not always decrease as altitude increases.
Global Distribution of Temperature
- The global distribution of temperature can be effectively understood by considering the temperature distribution for the month of January and July.
- The distribution of temperature is usually shown on the map using the isotherms.
- The isotherms are line joining places of equal temperature.
- Generally, the effects of latitude is well shown on the map as isotherms are generally parallel to the latitudes.
- The deviation from this trend is more generally observed in January rather than in July, especially in the northern hemisphere.
- The land surface is much larger in the northern hemisphere than the southern hemisphere. Hence, the effects of land masses and ocean currents are well observed.
Distribution of Temperature in January
- In January, there is winter in the Northern hemisphere and summers in the southern hemisphere.
- The western margins of continents in January are much higher than the Eastern counterparts as the westerlies can carry high temperatures into the landmasses.
- The temperature gradient is much closer to the Eastern margins of continents. The isotherms observe more steady behavior in the southern hemisphere.
Temperature Distribution in July
- During July, it is winter in the Southern hemisphere and summers in the Northern hemisphere. The isotherm behavior is the opposite of what it was in January.
- The isotherms are generally parallel to the latitudes in July.
- The equatorial oceans record warmer temperatures more than 27 degrees celsius.
- More than 30 degrees celsius is noticed over the land in the subtropical continent region of Asia, along the 30 ° N latitude.
Temperature Distribution in The World,Temperature Distribution in The World,Temperature Distribution in The World
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