{"id":1862,"date":"2015-01-25T16:09:09","date_gmt":"2015-01-25T21:09:09","guid":{"rendered":"http:\/\/site.extension.uga.edu\/climate\/?p=1862"},"modified":"2015-01-25T16:09:09","modified_gmt":"2015-01-25T21:09:09","slug":"desert-crusts-on-soil-provide-new-way-of-measuring-past-climate-in-southwest","status":"publish","type":"post","link":"https:\/\/site.extension.uga.edu\/climate\/2015\/01\/desert-crusts-on-soil-provide-new-way-of-measuring-past-climate-in-southwest\/","title":{"rendered":"Desert crusts on soil provide new way of measuring past climate in Southwest"},"content":{"rendered":"<p>How do\u00a0we know what the climate was before official measurements were taken?\u00a0 The historical instrumental records only go back to about the 1820s, when surgeons were the official observers at forts across the United States.<\/p>\n<p>To look at longer-term climate records, you have to use climate markers like tree rings to determine what the climate was.\u00a0 By studying the growth of modern tree species and comparing the ring thicknesses to the climate each year, you can determine what the temperature and precipitation was each year that the tree was alive.\u00a0 If you have trees living through overlapping time periods, you can compare ring patterns and create a serially complete picture of the climate over time.\u00a0 Over longer time periods, other &#8220;proxy&#8221; data like layers in sediment at the bottom of lakes or oceans can be used to do much the same thing, as well as layers of snow and ice (and volcanic ash) in glaciers and ice sheets like Antarctica.\u00a0 All of these collectively are called &#8220;paleoclimate data&#8221; and are combined to create long records of the climate on earth much farther back than instruments can do alone.<\/p>\n<p>This graph shows the time resolution you can get from various types of proxy data:<\/p>\n<figure id=\"attachment_1864\" aria-describedby=\"caption-attachment-1864\" style=\"width: 280px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/proxy_span_resolution_graph.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-1864\" src=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/proxy_span_resolution_graph-280x300.jpg\" alt=\"Source: UCAR\" width=\"280\" height=\"300\" srcset=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/proxy_span_resolution_graph-280x300.jpg 280w, https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/proxy_span_resolution_graph-129x138.jpg 129w, https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/proxy_span_resolution_graph.jpg 448w\" sizes=\"auto, (max-width: 280px) 100vw, 280px\" \/><\/a><figcaption id=\"caption-attachment-1864\" class=\"wp-caption-text\">Source: UCAR<\/figcaption><\/figure>\n<p>This week the Jornada Experimental Range in New Mexico posted a blog entry describing a new way of measuring climate variations using crusted soils in the desert Southwest (<a title=\"Desert SW soils and climate markers\" href=\"https:\/\/jornada.nmsu.edu\/blog\/identifying-climate-change-desert-southwest\" target=\"_blank\">link<\/a>).\u00a0 The development of these desert crusts is so slow that a slice just 1 millimeter thick contains a record 1000 years long.\u00a0 This is an exciting development because in the past it has been difficult to determine how climate changed in the past due to the lack of trees in the desert.\u00a0 This will give climate scientists new insight into how conditions there have changed over\u00a0a long time period.<\/p>\n<figure id=\"attachment_1863\" aria-describedby=\"caption-attachment-1863\" style=\"width: 300px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/Caliche-Dated.png\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1863\" src=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/Caliche-Dated-300x157.png\" alt=\"Source: Jornada\" width=\"300\" height=\"157\" srcset=\"https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/Caliche-Dated-300x157.png 300w, https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/Caliche-Dated-264x138.png 264w, https:\/\/site.extension.uga.edu\/climate\/files\/2015\/01\/Caliche-Dated.png 646w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-1863\" class=\"wp-caption-text\">Source: Jornada<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>How do\u00a0we know what the climate was before official measurements were taken?\u00a0 The historical instrumental records only go back to about the 1820s, when surgeons were the official observers at forts across the United States. To look at longer-term climate records, you have to use climate markers like tree rings to determine what the climate [&hellip;]<\/p>\n","protected":false},"author":58,"featured_media":1863,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,16],"tags":[],"class_list":["post-1862","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-climate-and-ag-in-the-news","category-climate-science"],"_links":{"self":[{"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/posts\/1862","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/users\/58"}],"replies":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/comments?post=1862"}],"version-history":[{"count":1,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/posts\/1862\/revisions"}],"predecessor-version":[{"id":1865,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/posts\/1862\/revisions\/1865"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/media\/1863"}],"wp:attachment":[{"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/media?parent=1862"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/categories?post=1862"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/climate\/wp-json\/wp\/v2\/tags?post=1862"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}