Climatic months and warm season aridity along the west coast of North America

Keywords: aridity, warm season, climatic months, North American west coast
Session Type: Virtual Paper Abstract
Day: Sunday
Session Start / End Time: 2/27/2022 08:00 AM (Eastern Time (US & Canada)) - 2/27/2022 09:20 AM (Eastern Time (US & Canada))
Room: Virtual 47

Abstract

Using a geographical climatology approach and working with the concept of climatic months, warm season aridity is examined for weather stations along the west coast of North America. Three indices of aridity that others have modified to work at a monthly time scale (i.e., Lang, de Martonne, and Walter and Lieth) are applied to 30-year normal climate data for June, July, and August for stations that extend from San Diego, CA to Juneau, AK. During July, places from San Diego northward to Aberdeen, WA fall within the arid class and locations further north into British Columbia are semi-arid. Details related to this geographic pattern of aridity indices will be shared for all three summer months and examined for the period of record at selected stations to identify variability and the frequency of arid months. An understanding from dynamic climatology of shifts in the polar jet stream related to Arctic amplification suggests that precipitation has and will continue to decrease in many west coast locations as the westerlies and summer storms weaken. Increasing warm season temperatures also push conditions toward greater aridity. The findings are linked to the possibility of human-induced aridification.