Question

Albuquerque, New Mexico, receives an average of 20.7 centimeters \((8.07\) inches) of rainfall annually. Albuquerque is considered a desert under the commonly used Köppen climate classification. The Russian city of Verkhoyansk is located near the Arctic Circle in Siberia. Yearly precipitation at Verkhoyansk averages 15.5 centimeters \((6.05\) inches \()\). about 5 centimeters ( 2 inches) less than Albuquerque, yet it is classified as a humid climate. Explain why this is the case.

Short answer

Verkhoyansk's low temperatures mean less moisture evaporates, creating humid conditions despite low rainfall, unlike hot deserts like Albuquerque.

Step-by-step solution

Understanding Climate Classification Systems

The Köppen climate classification system defines different climate types based on temperature and precipitation patterns. Deserts, for example, have low precipitation. However, the classification is complex and considers other factors like temperature.

Precipitation Comparison

Albuquerque receives about 20.7 cm of rainfall annually, whereas Verkhoyansk receives 15.5 cm. Despite Verkhoyansk receiving less precipitation, it is not classified as a desert.

Temperature Influence in Climate Classification

A key factor in the Köppen classification is temperature, particularly how it interacts with precipitation patterns over the year. Verkhoyansk, despite its low rainfall, experiences very low temperatures, which can cause the moisture to remain longer in the environment (i.e., not evaporating quickly as it might in warmer deserts like Albuquerque).

Humid vs Arid Conditions

Because Verkhoyansk is much colder, the low temperatures mean that even small amounts of precipitation can result in relatively humid conditions, as the cold climate prevents rapid evaporation, unlike in a hot desert.

Key concepts

Köppen Climate System

The Köppen Climate System is one of the most widely used methods for classifying the world's climates. It categorizes climates based on annual and monthly averages of temperature and precipitation. This system is practical because it reflects the plant life that can be found in a region, which is closely related to its climate.
In this classification system, climates are divided into five main groups, each denoted by a letter:

• A - Tropical
• B - Dry
• C - Temperate
• D - Continental
• E - Polar

Each group is further divided into subcategories. An essential aspect of the Köppen System is its attention to seasonal changes in temperature and precipitation.
This flexibility allows it to delineate various specific climates to a fine degree of detail, such as distinguishing between a cold desert and a hot desert.

Temperature Influence

Temperature plays a crucial role in the Köppen Climate System, influencing the classification of regions beyond their precipitation levels. While Albuquerque is considered a desert due to its warm temperatures and low rainfall, Verkhoyansk, situated near the Arctic Circle, is classified differently despite receiving less precipitation.
In cold climates like Verkhoyansk, temperatures hover far below freezing for much of the year. This means that moisture from the limited rainfall stays in the environment longer because low temperatures reduce evaporation rates considerably. The cooler climate allows even minimal moisture to create conditions that are perceived as humid rather than arid.
The interaction between temperature and precipitation is critical. In places with high temperatures, like Albuquerque, rainwater evaporates quickly, further reducing humidity and enforcing its desert classification.

Precipitation Patterns

Precipitation patterns are another critical component of climate classification. These patterns not only involve the total annual precipitation a region receives but also its seasonal distribution. A climate might be classified differently if it receives the same annual rainfall but in varying quantities throughout the year.
Albuquerque receives its precipitation mainly in the summer months, contributing to its designation as a desert, displayed in significant dry periods within the year. In contrast, Verkhoyansk has a different pattern where even the small amount of precipitation is spread over colder months. This distribution, combined with low evaporation rates due to cold temperatures, influences its classification.

Humidity Conditions

Humidity conditions are affected by both temperature and precipitation. Humidity refers to the amount of moisture in the air, which changes depending on how much water can evaporate into the atmosphere. Albuquerque's warm temperatures allow for more evaporation, meaning even if there is rain, it doesn’t result in high humidity.
By contrast, colder climates like that of Verkhoyansk feature low evaporation due to the persistent cold. Thus, even small amounts of precipitation can contribute to a sense of humidity or moisture in the air.
This difference helps explain why Verkhoyansk, despite receiving less rain than Albuquerque, is considered humid. It’s not just about how much rain falls, but how the environment retains that moisture, influencing perceptions of humidity.