AMS Climate Science and Climatology 2

Question 1

El Niño conditions in the tropical Pacific are characterized by:

Accepted Answer

Warmer-than-normal SSTs in the central and eastern tropical Pacific

Answer

El Niño is defined by anomalously warm sea surface temperatures in the central and eastern equatorial Pacific, which weaken the Walker circulation and alter global weather patterns.

Question 2

The Oceanic Niño Index (ONI) measures El Niño and La Niña events using SST anomalies in which Pacific region?

Accepted Answer

Niño 3.4 (central equatorial Pacific)

Answer

NOAA's ONI is based on a 3-month running mean of SST departures from average in the Niño 3.4 region (5°N–5°S, 120°W–170°W), with ±0.5°C defining El Niño/La Niña.

Question 3

The Pacific Decadal Oscillation (PDO) differs from ENSO primarily in that:

Accepted Answer

The PDO operates on decadal timescales, while ENSO operates on 2–7 year timescales

Answer

The PDO is a long-lived pattern of Pacific SST variability with phases lasting 20–30 years, much longer than ENSO's 2–7 year cycle, and modulates ENSO's impacts on North America.

Question 4

A positive phase of the North Atlantic Oscillation (NAO) is associated with:

Accepted Answer

Stronger westerlies and warmer, wetter winters over northwestern Europe

Answer

A positive NAO features an enhanced pressure gradient between the Azores High and Icelandic Low, driving stronger westerlies that bring mild, wet conditions to northwestern Europe and northern Eurasia.

Question 5

What is a climate teleconnection?

Accepted Answer

A statistical relationship linking climate anomalies in geographically distant regions

Answer

Teleconnections are recurring and persistent large-scale patterns of pressure and circulation anomalies that span vast geographical areas and link climate variations in distant regions.

American Meteorological Society Certification Practice Test

American Meteorological Society Certification Practice Test

AMS Climate Science and Climatology 2